and foundation installation, during which time we may make changes to our recommendations if deemed necessary.
We appreciate the opportunity to provide our services to you on this project. Should you have any questions, please call.
Sincerely,
ROCKRIDGE GEOTECHNICAL, INC.
Linda H.J. Liang, P.E., G.E. Alex D. Limpert, P.E.
Principal Engineer Project Engineer
Enclosure
QUALITY CONTROL REVIEWER:
Craig S. Shields, P.E., G.E.
Principal Engineer
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TABLE OF CONTENTS
1.0 INTRODUCTION ...............................................................................................................1
2.0 SCOPE OF SERVICES .......................................................................................................1
3.0 FIELD INVESTIGATION AND LABORATORY TESTING...........................................2
3.1 Test Boring...............................................................................................................2
3.2 Laboratory Testing...................................................................................................3
4.0 SUBSURFACE CONDITIONS ..........................................................................................4
4.1 Groundwater ............................................................................................................4
5.0 SEISMIC CONSIDERATIONS ..........................................................................................5
5.1 Regional Seismicity and Faulting ............................................................................5
5.2 Geologic Hazards.....................................................................................................7
5.2.1 Ground Shaking ...........................................................................................7
5.2.2 Ground Surface Rupture ..............................................................................7
5.2.3 Liquefaction and Liquefaction-Induced Hazards.........................................8
5.2.4 Cyclic Densification.....................................................................................9
6.0 CONCLUSIONS AND RECOMMENDATIONS ............................................................10
6.1 Site Preparation and Fill Placement.......................................................................10
6.1.1 Utility Trench Backfill...............................................................................11
6.2 Foundations and Settlement...................................................................................12
6.2.1 Existing and New Spread Footings............................................................13
6.3 New Slab-on-Grade Floor......................................................................................13
6.4 Permanent Below-Grade Walls..............................................................................14
6.5 Seismic Design.......................................................................................................16
6.6 Soil Corrosivity......................................................................................................17
6.7 Construction Considerations..................................................................................17
7.0 GEOTECHNICAL SERVICES DURING CONSTRUCTION ........................................18
8.0 LIMITATIONS..................................................................................................................18
REFERENCES
FIGURES
APPENDIX A – Log of Boring
APPENDIX B – Laboratory Test Results
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LIST OF FIGURES
Figure 1 Site Location Map
Figure 2 Site Plan
Figure 3 Regional Geologic Map
Figure 4 Regional Faults and Historic Seismicity Map
Figure 5 Liquefaction Susceptibility Map
APPENDIX A
Figure A-1 Log of Boring, B-1
Figure A-2 Classification Chart
APPENDIX B
Figure B-1 Plasticity Chart
Figure B-2 Particle Size Distribution Chart
Figure B-3 Soil Corrosivity Test Results
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GEOTECHNICAL INVESTIGATION
PROPOSED RENOVATION AND ADDITION
401 SAN ANSELMO AVENUE
San Anselmo, California
1.0 INTRODUCTION
This report presents the results of the geotechnical investigation performed by Rockridge Geotechnical, Inc. (Rockridge) for the proposed renovation and addition to the existing building at 401 San Anselmo Avenue in San Anselmo, California. The site is on the northwestern corner of the intersection of San Anselmo Avenue and Pine Street, as shown on the Site Location Map (Figure 1).
The subject property is bordered by a parking lot to the west, a commercial building to the north, San Anselmo Avenue to the east, and Pine Street to the south. The site is trapezoidal shaped with maximum plan dimensions of about 40 feet by 75 feet, as shown on the Site Plan (Figure 2). The ground surface at the site and vicinity is relatively flat. Currently, the site is entirely occupied by a one- and two-story building previously used as a bank. The southern half of the building was constructed in 1925 and the northern half was constructed later as part of an expansion for the bank. The eastern two-thirds of the building is two stories with a partial mezzanine and the western third of the building is one story. Information regarding the building foundation type and depth was not available when this report was prepared. We encountered a 7-inch-thick concrete floor slab at our test boring location. We assume the existing building is supported on spread footings.
Plans are to convert the existing building into a mixed-use property, including the addition of a third story. Plans include commercial use on the ground floor and residential units on the second and third floors.
2.0 SCOPE OF SERVICES
Our investigation was performed in accordance with our proposal dated September 11, 2023. Our scope of services consisted of exploring subsurface conditions at the site by drilling one test DRAFT
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boring, performing laboratory testing on selected soil samples, and performing engineering analyses to develop conclusions and recommendations regarding:
• soil and groundwater conditions at the site
• site seismicity and seismic hazards, including the potential for liquefaction and liquefaction-induced ground failure
• the most appropriate foundation type(s) for the proposed renovation and addition • design criteria for the recommended foundation type(s), including vertical and lateral capacities for each of the foundation type(s)
• estimates of foundation settlement
• permanent wall design pressures, where needed
• site grading and fill placement, including criteria for fill quality and compaction • subgrade preparation for new slab-on-grade floors
• corrosivity of the near-surface soil and the potential effects on buried concrete and metal structures and foundations
• 2022 California Building Code (CBC) site class and design spectral response acceleration parameters
• construction considerations.
3.0 FIELD INVESTIGATION AND LABORATORY TESTING
We explored the subsurface conditions at the site by drilling one test boring and performing laboratory testing on selected soil samples. Before drilling, we obtained a drilling permit from Marin County Environmental Health Services (MCEHS). We also contacted Underground Services Alert (USA) to notify them of our work, as required by law, and retained C. Cruz SubSurface Locators, a private utility locator, to check the boring location to reduce the potential for encountering buried utilities during drilling. Details of our field investigation and laboratory testing are presented in this section.
3.1 Test Boring
One test boring, designated as Boring B-1, was drilled on October 2, 2023, by Stapleton Engineering and Exploration of Santa Rosa, California, at the approximate location shown on Figure 2. We advanced an 8-inch-diameter core through the concrete floor slab at the borehole location; the concrete slab was measured to be 7 inches thick.
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Boring B-1 was drilled to a depth of 37-1/2 feet below the top of the slab (bts) using a portable drill rig equipped with 4-inch-outside-diameter solid-stem flight augers. During drilling, our field engineer logged the soil encountered and obtained representative samples for visual classification and laboratory testing. Our field engineer noted the date and time when groundwater was encountered during drilling. The boring log is presented in Figure A-1 in Appendix A. The soil encountered in the boring was classified in accordance with the classification system presented in Figure A-2.
Soil samples were obtained using the Modified California (MC) split-barrel sampler with a 3.0- inch outside diameter and 2.5-inch inside diameter, lined with 2.43-inch-inside-diameter stainless steel tubes. The sampler was driven with a 140-pound rope-and-cathead safety hammer falling about 30 inches per drop. The sampler was driven up to 18 inches, and the hammer blows required to drive the sampler were recorded every 6 inches and are presented on the boring log. A “blow count” is defined as the number of hammer blows per 6 inches of penetration or 50 blows for 6 inches or less of penetration. The blow counts required to drive the MC sampler were converted to approximate Standard Penetration Test (SPT) N-values using a factor of 0.7 to account for sampler type and approximate hammer energy. The blow counts used for this conversion were the last two blow counts. The converted SPT N-values are presented on the boring log.
Upon completion of drilling, the borehole was backfilled with neat cement grout in accordance with MCEHS requirements and patched with concrete. Soil cuttings from the borehole were placed in four 5-gallon buckets and left on-site.
3.2 Laboratory Testing
We re-examined each soil sample in the office to confirm the field classification and selected representative samples for laboratory testing. Laboratory tests were performed by B. Hillebrandt Soils Testing, Inc. of Alamo, California to measure moisture content, dry density, particle size distribution, and plasticity (Atterberg limits). Laboratory tests were performed by Project X Corrosion Engineering of Murrieta, California on one near-surface soil sample to provide data DRAFT
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for evaluating the soil corrosivity. The results of the laboratory tests are presented on the boring logs and in Appendix B.
4.0 SUBSURFACE CONDITIONS
Regional geologic information (Figure 3) indicates the site is underlain by Holocene-age alluvium (Qha). The results of our boring indicate the building is underlain by alluvium to the maximum depth explored of 37-1/2 feet bts. The alluvium consists of stiff to very stiff clay with variable silt and sand content interbedded with loose to medium dense sand with variable clay and gravel content.
4.1 Groundwater
Groundwater was initially encountered at a depth of 18-1/2 feet bts and rose to 17 feet bts prior to grouting. The groundwater levels measured in the boring may not have stabilized at the time when the measurements were taken.
To further estimate the groundwater level at the site, we reviewed information on the State of California Water Resources Control Board GeoTracker website. 1 From the GeoTracker website,
we obtained information from monitoring wells installed at 343 San Anselmo Avenue, about 150 feet south of the site. A summary of groundwater-level measurements presented in the Quarterly Groundwater Monitoring Report, 3rd Calendar Quarter 2001, prepared by Hanover Incorporated and dated October 30, 2001, indicates the groundwater level was measured between June 2000 and August 2001. Measured groundwater levels ranged from 7.73 to 11.27 feet below the ground surface.
The depth to groundwater is expected to vary several feet annually depending on rainfall amounts. We recommend a design groundwater level at the site to be 7 feet bts. 1 https://geotracker.waterboards.ca.gov/
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5.0 SEISMIC CONSIDERATIONS
5.1 Regional Seismicity and Faulting
The site is located within the Coast Ranges Geomorphic Province of California, which is characterized by northwest-trending valleys and ridges. These topographic features are controlled by folds and faults that resulted from the collision of the Farallon and North American plates and subsequent strike-slip faulting along the San Andreas Fault system. The San Andreas Fault is more than 600 miles long and extends from Point Arena in the north to the Gulf of California in the south. The Coast Ranges Geomorphic Province is bounded on the east by the Great Valley and on the west by the Pacific Ocean.
The major active faults in the area are the San Andreas, San Gregorio, and Hayward faults. These and other faults in the region are shown on Figure 4. For these and other active faults within a 50-kilometer radius of the site, the distance from the site and estimated characteristic moment magnitude2[Petersen et al. (2014) & Thompson et al. (2016)] are summarized in Table 1. These references are based on the Third Uniform California Earthquake Rupture Forecast (UCERF3), prepared by Field et al. (2013).
2 Moment magnitude (Mw) is an energy-based scale and provides a physically meaningful measure of the size of a faulting event. Moment magnitude is directly related to average slip and fault rupture area.
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TABLE 1
Regional Faults and Seismicity
Fault Segment
Approximate
Distance
from Site
(km)
Direction from
Site
Characteristic
Moment
Magnitude
Total North San Andreas
(SAO+SAN+SAP+SAS) 12 Southwest 8.04
North San Andreas (North Coast,
SAN) 12 Southwest 7.52
North San Andreas (Peninsula, SAP) 12 Southwest 7.38
San Gregorio (North) 13 West 7.44
Total Hayward + Rodgers Creek
(RC+HN+HS+HE) 16 Northeast 7.58
Hayward (North, HN) 16 Northeast 6.90
Rodgers Creek - Healdsburg 24 Northeast 7.19
West Napa 35 Northeast 6.97
Hayward (South, HS) 40 East 7.00
Green Valley 42 East 6.30
Concord 42 East 6.45
Mount Diablo Thrust North CFM 46 East 6.72
Mount Diablo Thrust 47 East 6.67
Total Calaveras (CN+CC+CS+CE) 48 East 7.43
Calaveras (North, CN) 48 East 6.86
Damaging earthquakes have occurred along many of these faults in recorded history, as depicted on Figure 4 (USGS, 2021). Notable historic earthquakes which have impacted the Bay Area in recorded history include:
• 1838 San Andreas Earthquake, Mw = 7.4 (estimated)
• 1865 San Andreas Earthquake, Mw = 6.5 (estimated)
• 1868 Hayward Earthquake, Mw = 7.0 (estimated)
• 1906 Great San Francisco Earthquake (San Andreas Fault), Mw = 7.9 (estimated) • 1989 Loma Prieta Earthquake (San Andreas Fault), Mw = 6.9 DRAFT
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• 2014 West Napa Earthquake, Mw = 6.0
As a part of the UCERF3 project, researchers estimated that the probability of at least one Mw ≥ 6.7 earthquake occurring in the greater San Francisco Bay Area during a 30-year period (starting in 2014) is 72 percent. The highest probabilities are assigned to sections of the Hayward (South), Calaveras (Central), and San Andreas (Santa Cruz Mountains) faults. The respective probabilities are approximately 25, 21, and 17 percent.
5.2 Geologic Hazards
Because the project site is in a seismically active region, we evaluated the potential for earthquake-induced geologic hazards including ground shaking, ground surface rupture, liquefaction,3lateral spreading,4and cyclic densification. 5 We used the results of our
geotechnical investigation to evaluate the potential of these phenomena occurring at the site.
5.2.1 Ground Shaking
The seismicity of the site is governed by the activity of the San Andreas Fault, although ground shaking from future earthquakes on other faults, including the Hayward and San Gregorio faults, will also be felt at the site. The intensity of earthquake ground motion at the site will depend upon the characteristics of the generating fault, distance to the earthquake epicenter, and magnitude and duration of the earthquake. We judge that strong to very strong ground shaking could occur at the site during a large earthquake on one of the nearby faults.
5.2.2 Ground Surface Rupture
Historically, ground surface displacements closely follow the trace of geologically young faults.
The site is not within an Earthquake Fault Zone, as defined by the Alquist-Priolo Earthquake Fault Zoning Act, and no known active or potentially active faults exist on the site. Therefore, we 3 Liquefaction is a phenomenon where loose, saturated, cohesionless soil experiences temporary reduction in strength during cyclic loading such as that produced by earthquakes. 4 Lateral spreading is a phenomenon in which surficial soil displaces along a shear zone that has formed within an underlying liquefied layer. Upon reaching mobilization, the surficial blocks are transported downslope or in the direction of a free face by earthquake and gravitational forces. 5 Cyclic densification is a phenomenon in which non-saturated, cohesionless soil is compacted by earthquake vibrations, causing ground-surface settlement.
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conclude the probability of fault offset at the site from a known active fault to be very low. In a seismically active area, the remote possibility exists for future faulting in areas where no faults previously existed; however, we conclude that the probability of surface faulting, and consequently secondary ground failure from previously unknown faults, is very low.
5.2.3 Liquefaction and Liquefaction-Induced Hazards
When a saturated, cohesionless soil liquefies, it experiences a temporary loss of shear strength created by a transient rise in excess pore pressure generated by a strong ground motion. Soil susceptible to liquefaction includes loose to medium dense sand and gravel, low-plasticity silt, and some low-plasticity clay deposits. Flow failure, lateral spreading, differential settlement, loss of bearing strength, ground fissures, and sand boils are evidence of excess pore pressure generation and liquefaction.
The site is within a zone of high liquefaction susceptibility as shown on the map titled Liquefaction Susceptibility Map 2-11, San Francisco Bay Region, California, prepared by U.S.
Geological Survey in 2000 (see Figure 5). We evaluated the liquefaction potential of soil encountered below the groundwater table at the site using data collected from our boring and the methodology proposed by Youd et al. (2001).
Our analyses were performed using an assumed high groundwater depth of 7 bts for the “during earthquake” groundwater level. In accordance with the 2022 CBC, we used a peak ground acceleration of 0.63 times gravity (g) in our liquefaction evaluation; this peak ground acceleration is consistent with the Maximum Considered Earthquake Geometric Mean (MCEG) peak ground acceleration adjusted for site effects (PGAM). We also used a moment magnitude
8.04 earthquake, which is consistent with the characteristic moment magnitude for the San Andreas Fault event, as presented on Table 1.
Our liquefaction analyses indicate the sandy silty clay layer between 14 and 20 feet bts is susceptible to cyclic softening during a major seismic event. Our liquefaction analyses also indicate there are interbedded medium dense sand and clayey sand layers present between depths of 20 and 34 feet bts that are susceptible to liquefaction during a major earthquake. Based on the results of our analyses, we estimate total “free-field” ground settlement associated with DRAFT
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liquefaction after an MCE event generating a PGAM of 0.63g will be up to about 2-1/2 inches.
We estimate liquefaction-induced differential settlement will be up to about 1-1/2 inches over a horizontal distance of 30 feet.
Liquefaction-Induced Hazards
Ishihara (1985) presented an empirical relationship that provides criteria used to evaluate whether liquefaction-induced ground failure, such as sand boils, would be expected to occur under a given level of shaking for a liquefiable layer of given thickness overlain by a resistant, or protective, surficial layer. Considering the ground surface at the site is entirely confined by a concrete floor slab and the non-liquefiable soil overlying the soil layers susceptible to surface manifestation (i.e., granular layers with N1(60) below 10 blows per foot) is relatively thick, we conclude the potential for surface manifestations from liquefaction, such as sand boils, to be low.
The site is underlain by about 14 feet of stiff to very stiff clay overlying soil susceptible to cyclic softening and liquefaction. Therefore, we conclude the potential for loss of bearing for shallow foundations, such as spread footings, underlain by 10 to 12 feet of stiff to very stiff clay to be low.
Lateral spreading occurs when a continuous layer of soil liquefies at a depth and the soil layers above move toward an unsupported face, such as a shoreline slope, or in the direction of a regional slope or gradient. Based on the lack of controlling boundary conditions (ground surface at the site and vicinity is relatively flat) and the soil layers susceptible to lateral spreading (i.e., granular layers with N1(60) below 15 blows per foot) are relatively thin and likely discontinuous, we conclude the potential for lateral spreading to occur at the site is low.
5.2.4 Cyclic Densification
Cyclic densification (also referred to as differential compaction) of non-saturated sand (sand above the groundwater table) can occur during an earthquake, resulting in settlement of the ground surface and overlying improvements. The results of our boring indicate that the soil above the groundwater at the site is not susceptible to cyclic densification due to its cohesion.
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Therefore, we conclude that the potential for ground surface settlement resulting from cyclic densification at the site is very low.
6.0 CONCLUSIONS AND RECOMMENDATIONS
From a geotechnical standpoint, we conclude the proposed renovation and addition can be constructed as planned, provided the recommendations presented in this report are incorporated into the project plans and specifications and implemented during construction. The primary geotechnical issues at the site are: 1) the potential for up to about 1-1/2 inches of liquefactioninduced differential settlement across a horizontal distance of 30 feet, and 2) providing adequate vertical and lateral support for the proposed improvements. Our conclusions and recommendations regarding foundation support and other geotechnical aspects of the project are presented in this section.
6.1 Site Preparation and Fill Placement
In areas that will receive fill or improvements (i.e., new building pad subgrade), the soil subgrade exposed should be scarified to a depth of at least eight inches, moisture-conditioned to above optimum moisture content, and compacted to at least 90 percent relative compaction. 6 If
the subgrade consists of clean sand or gravel (defined as soil with less than 5 percent fines by weight) or is within 8 inches of finished subgrade in areas to receive vehicular traffic, it should be moisture-conditioned to above optimum moisture content and compacted to at least 95 percent relative compaction.
Fill should consist of on-site soil or imported soil (select fill) that is free of organic matter, contain no rocks or lumps larger than 3 inches in greatest dimension, and be approved by the Geotechnical Engineer. Imported soil (select fill) should also have a liquid limit of less than 40 and plasticity index of less than 12. Samples of proposed select fill material should be submitted to the Geotechnical Engineer at least three business days prior to use at the site. The grading contractor should provide analytical test results or other suitable environmental documentation 6 Relative compaction refers to the in-place dry density of soil expressed as a percentage of the maximum dry density of the same material, as determined by the ASTM D1557 laboratory compaction procedure.
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indicating the imported fill is free of hazardous materials at least three days before use at the site.
If this data is not provided, a minimum of two weeks will be required to perform any necessary analytical testing.
Fill should be placed in horizontal lifts not exceeding 8 inches in uncompacted thickness, moisture-conditioned to above optimum moisture content and compacted to at least 90 percent relative compaction. Fill consisting of clean sand or gravel (defined as soil with less than 5 percent fines by weight) or greater than 5 feet thick should be compacted to at least 95 percent relative compaction. Fill placed within 8 inches of soil subgrade for pavement that will be subjected to vehicular traffic, as well as the overlying Class 2 aggregate base, should be compacted to at least 95 percent relative compaction and be non-yielding.
6.1.1 Utility Trench Backfill
Excavations for utility trenches can be readily made with a backhoe. All temporary excavations used in construction should be designed, planned, constructed, and maintained by the contractor and should conform to the current CAL-OSHA requirements. To provide uniform support, pipes or conduits should be bedded on a minimum of 4 inches of clean sand or fine gravel. After the pipes and conduits are tested, inspected (if required) and approved, they should be covered to a depth of 6 inches with clean sand or fine gravel, which should be mechanically tamped. The pipe bedding and cover should be eliminated where a low-permeability plug is required as described below.
Backfill for utility trenches and other excavations is also considered fill and should be placed and compacted according to the recommendations presented previously. If imported clean sand or gravel (defined as soil with less than 5 percent fines) is used as backfill, it should be compacted to at least 95 percent relative compaction. Jetting of trench backfill should not be permitted.
Special care should be taken when backfilling utility trenches in pavement areas. Poor compaction may cause excessive settlements, resulting in damage to the pavement section.
Foundations should be bottomed below an imaginary line extending up at a 1.5:1 (horizontal to vertical) inclination from the base of utility trenches running parallel to the foundations.
Alternatively, the portion of the utility trench (excluding bedding) that is below the 1.5:1 line can DRAFT
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be backfilled with controlled low-strength material (CLSM) with a 28-day unconfined compressive strength of at least 100 pounds per square inch (psi). If utility trenches are to be excavated below this 1.5:1 line adjacent to existing foundations or after construction of new building foundations, the trench walls need to be fully supported with shoring until CLSM is placed.
Where utility trenches enter the building pad, a low-permeability plug consisting of sand-cement slurry, at least 3 feet in length, should be installed where the trenches enter the building footprint.
6.2 Foundations and Settlement
Existing foundation plans were not available when we prepared this report, but we assume the building is supported on spread footings. As discussed in Section 5.2.3, the building is underlain by 14 feet of stiff to very stiff clay overlying soil that is susceptible to cyclic softening and liquefaction. We estimate total and differential settlements resulting from liquefaction of about 2- 1/2 inches and 1-1/2 inches across a horizontal distance of 30 feet, respectively, may occur during an MCE event generating a PGA of 0.63g. According to Section 12.13.9.2 of ASCE 7-16, individual footings should be interconnected by ties (i.e., grade beams) if the seismically induced differential settlement exceeds 1.8 inches over a horizontal distance of 30 feet for a building in Risk Category II.
Based on the results of our investigation, we conclude the existing building and proposed renovation and addition may be supported on spread footings. Although the estimated potential seismically included differential settlement is less than 1.8 inches over a horizontal distance of 30 feet and thus foundation ties for individual footings are not required by Section 12.13.9.2 of ASCE 7-16 to address seismically induced differential settlements, we recommend the proposed improvements be supported on interconnected continuous footings to reduce the effects of combined static and seismically induced differential settlements. We also recommend existing individual footings be interconnected by ties to improve building performance during a major earthquake.
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6.2.1 Existing and New Spread Footings
Where existing foundations consist of isolated spread footings, we recommend grade beams be constructed to tie the isolated footings together to form a stiffened foundation system. Existing and new interconnected continuous footings should be at least 18 inches wide. Interconnected spread footings may be designed using an allowable bearing pressure of 3,500 pounds per square foot (psf) for dead-plus-live loads; this value may be increased by one-third for total loads, which include wind or seismic forces. The allowable bearing pressures for dead-plus-live and total loads include factors of safety of at least 2.0 and 1.5, respectively.
We judge settlement of existing footings under existing loads are complete. We estimate total and differential static settlements for existing footings subjected to new loads and new footings will not exceed 3/4 inch and 1/2 inch over a horizontal distance of 30 feet, respectively.
Lateral loads may be resisted by a combination of passive pressure on the vertical faces of the footings and friction between the bottoms of the footings and the supporting soil. To compute lateral resistance, we recommend using a uniform pressure of 1,500 psf for transient loads and an equivalent fluid weight (triangular distribution) of 260 pounds per cubic foot (pcf) for sustained loads; the upper foot of soil should be ignored unless confined by a slab or pavement. Frictional resistance should be computed using a base friction coefficient of 0.3. The passive pressure and frictional resistance values include a factor of safety of at least 1.5 and may be used in combination without further reduction.
Footing excavations should be free of standing water, debris, and disturbed materials prior to placing concrete. The bottoms and sides of the footing excavations should be kept moist until concrete is placed in the excavations. We should check footing excavations prior to placement of reinforcing steel to check for proper bearing and preparation.
6.3 New Slab-on-Grade Floor
The subgrade for new slab-on-grade floor, if any, should be prepared in accordance with our recommendations in Section 6.1. Where water vapor transmission through the floor slab is not desirable, we recommend installing a capillary moisture break and water vapor retarder beneath DRAFT
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the floor slab. A capillary moisture break consists of at least 4 inches of clean, free-draining gravel or crushed rock. The particle size of the capillary break material should meet the gradation requirements presented in Table 2.
TABLE 2
Gradation Requirements for Capillary Moisture Break
Sieve Size Percentage Passing Sieve
1 inch 90 – 100
¾ inch 30 – 100
½ inch 5 – 25
3/8 inch 0 – 6
The vapor retarder should meet the requirements for Class B vapor retarders stated in ASTM E1745. The vapor retarder should be placed in accordance with the requirements of ASTM E1643. These requirements include overlapping seams by 6 inches, taping seams, and sealing penetrations in the vapor retarder.
Concrete mixes with high water/cement (w/c) ratios result in excess water in the concrete, which increases the cure time and results in excessive vapor transmission through the slab. Therefore, concrete for the floor slab should have a low w/c ratio - less than 0.50. If the concrete is poured directly over the vapor retarder, we recommend the w/c ratio of the concrete not exceed 0.45. In either case, water should not be added to the concrete mix in the field. If necessary, workability should be increased by adding plasticizers. In addition, the slab should be properly cured. Before the floor covering is placed, the contractor should check that the concrete surface and the moisture emission levels (if emission testing is required) meet the manufacturer’s requirements.
6.4 Permanent Below-Grade Walls
Permanent below-grade walls should be designed to resist lateral earth pressures imposed by the retained soil, as well as a surcharge pressure from nearby foundations and vehicles where appropriate. Walls that will retain more than 6 feet of soil will need to be designed for the more critical of static or seismic conditions.
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For static conditions, we recommend restrained and unrestrained walls be designed for the following lateral earth repressures:
• Restrained Wall - At-rest earth pressure using an equivalent fluid weight of 55 pcf for drained conditions and 89 pcf for undrained conditions. • Unrestrained Wall - Active earth pressure using an equivalent fluid weight of 35 pcf for drained conditions and 79 pcf for undrained conditions.
Walls that will retain more than 6 feet of soil will need to be designed for the more critical of static (presented above) or the following seismic conditions. • Restrained Wall - Active earth pressure using an equivalent fluid weight of 35 pcf plus a seismic increment of 25 pcf for drained conditions; and 79 pcf plus a seismic increment of 12 pcf for undrained conditions.
• Unrestrained Wall - Active earth pressure using an equivalent fluid weight of 35 pcf plus a seismic increment of 10 pcf for drained conditions; and 79 pcf plus a seismic increment of 5 pcf for undrained conditions.
Where there will be vehicular traffic behind the top of a permanent wall within a horizontal distance equal to 1.5 times the height of the wall, the wall should be designed for vehicular surcharge of 50 psf over the entire height of the wall. Where existing foundations are supported above a “zone-of-influence” line extending up from a permanent wall at an inclination of 1.5:1 (horizontal to vertical), the wall should be designed for a surcharge pressure. The magnitude of the surcharge pressure will need to be evaluated on a case-by-case basis.
To protect against moisture migration, below-grade walls should be waterproofed and water stops should be placed at all construction joints. Although the below-grade walls will be above the design groundwater level, water can accumulate behind the walls from other sources, such as rainfall, irrigation, and broken water lines, etc. If the “drained” earth pressures presented above are used to design the walls, they will need to incorporate a drainage system. Alternatively, the walls may be designed for the recommended “undrained” earth pressures presented above over their entire height, in which case the drainage system may be omitted.
One acceptable method for backdraining below-grade walls is to place a prefabricated drainage panel against the back of the wall. The drainage panel should extend down to a perforated PVC DRAFT
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collector pipe at the base of the wall. The pipe should be surrounded on all sides by at least 4 inches of Caltrans Class 2 permeable material or 3/4-inch drain rock wrapped in filter fabric (Mirafi NC or equivalent). A proprietary, prefabricated collector drain system, such as Tremdrain Total Drain or Hydroduct Coil (or equivalent), designed to work in conjunction with the drainage panel may be used in lieu of the perforated pipe surrounded by gravel described above. The pipe should be connected to a suitable discharge point; a sump and pump system may be required to drain the collector pipes.
6.5 Seismic Design
As discussed in Section 5.2.3, the site is underlain by potentially liquefiable soil. For design in accordance with 2022 CBC, a Site Class F would be used and site-specific response spectra would be needed. However, considering the building with the proposed addition will have a period of 0.5 second or less, ASCE 7-16 does not require site-specific evaluations. Hence, for seismic evaluation where the building period is less than 0.5 second, we recommend Site Class D be used.
The latitude and longitude of the site are 37.9739° and -122.5625 °, respectively. For design per the 2022 CBC, we recommend the following:
• Site Class D (stiff soil, non-default)
• SS = 1.50g, S1 = 0.60g
The 2022 CBC is based on the guidelines contained within ASCE 7-16 (Supplement 3 revision), which stipulates that where S1 is greater than 0.2 times gravity (g) for Site Class D, a ground motion hazard analysis is required unless the long-period spectral design parameters (SM1, SD1) are increased by 50%. Therefore, we recommend the following seismic design parameters, which include the 50% increase as designated by an asterisk:
• Fa = 1.0, Fv = 1.7
• SMS = 1.50g, SM1* = 1.53g
• SDS = 1.00g, SD1* = 1.02g
• Seismic Design Category D for Risk Factors I, II, and III DRAFT
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23-2488 17 November 6, 2023
6.6 Soil Corrosivity
Corrosivity tests were performed by Project X Corrosion Engineering of Murrieta, California on a soil sample obtained from B-1 at a depth of 1-1/2 feet bts. The corrosivity test results are presented in Appendix B of this report.
Many factors can affect the corrosion potential of soil including, but not limited to, resistivity, pH, and chloride and sulfate concentrations. Based on the minimum soil resistivity measurements of 1,742 ohm-cm, we conclude the soil is “highly corrosive” to buried metal (Roberge, 2018). Accordingly, all buried iron, steel, cast iron, galvanized steel, and dielectriccoated steel or iron should be protected against corrosion depending upon the critical nature of the structure. If it is necessary to have metal in contact with soil, a corrosion engineer should be consulted to provide recommendations for corrosion protection.
The results of the pH test (7.7) indicate the near-surface soil is “negligibly corrosive” to buried metallic and concrete structures. The chloride ion concentration (12.5 mg/kg) indicates the chlorides in the near-surface soil are “negligibly corrosive” to buried metallic structures and reinforcing steel in concrete structures below ground. The results also indicate the sulfate ion concentration (62.9 mg/kg) is sufficiently low such that sulfates do not pose a threat to buried concrete and mortars.
6.7 Construction Considerations
The soil to be excavated for the new footings is expected to consist of alluvium. Due to overhead restrictions in certain areas and proximity to existing foundations, limited access or hand excavation equipment should be used.
Excavations that will be entered by workers should be shored or sloped in accordance with the Occupational Safety and Health Administration (OSHA) standards (29 CFR Part 1926). Where space permits, the sides of excavations may be sloped. We recommend the inclination of temporary construction slopes be no steeper than 1:1 in clayey soil (OSHA Type B Soil). Where space does not permit sloping of the excavation perimeter, a shoring system will be required to support the sides of the proposed excavation. The contractor should be responsible for the DRAFT
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23-2488 18 November 6, 2023
construction and safety of temporary slopes. The shoring designer should be responsible for the shoring design.
Heavy equipment should not be used within the existing building and 10 horizontal feet from adjacent shallow foundations. Jumping jack or hand-operated vibratory plate compactors should be used for compacting fill within this zone.
7.0 GEOTECHNICAL SERVICES DURING CONSTRUCTION
Prior to construction, Rockridge Geotechnical, Inc. should review the project plans and specifications to check that they conform to the intent of our recommendations. During construction, our field engineer should observe foundation excavations prior to placement of reinforcing steel and perform field density testing to check subgrade preparation and fill compaction. These observations will allow us to compare actual with anticipated soil conditions and to check that the contractor's work conforms to the geotechnical aspects of the plans and specifications.
8.0 LIMITATIONS
This geotechnical investigation has been conducted in accordance with the standard of care commonly used as state-of-practice in the profession. No other warranties are either expressed or implied. The recommendations made in this report are based on the assumption that the subsurface conditions do not deviate appreciably from those disclosed in our field investigation.
If any variations or undesirable conditions are encountered during construction, we should be notified so that additional recommendations can be made, where appropriate. The foundation recommendations presented in this report are developed exclusively for the proposed project described in this report and are not valid for other locations and construction in the project vicinity.
DRAFT
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REFERENCES
American Society of Civil Engineers (ASCE). (2017). ASCE/SEI 7-16: Minimum Design Loads and Associated Criteria for Buildings and Other Structures. ASCE Publications. http://doi.org/10.1061/9780784414248
California Department of General Services. (2022). California Building Code. State Government of California. https://www.dgs.ca.gov/BSC/Codes
California Department of Transportation (Caltrans). (2022). Caltrans Standard Specifications.
State Government of California. https://dot.ca.gov/-/media/dotmedia/programs/design/documents/2022_stdspecs-a11y.pdf Field, E.H., Biasi, G.P., Bird, P., Dawson, T.E., Felzer, K.R., Jackson, D.D., Johnson, K.M., Jordan, T.H., Madden, C., Michael, A.J., Milner, K.R., Page, M.T., Parsons, T., Powers, P.M., Shaw, B.E., Thatcher, W.R., Weldon, R.J., & Zeng, Y. (2013). Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3)—The Time-Independent Model (Open-File Report 2013- 1165). United States Geological Survey. http://doi.org/10.3133/ofr20131165 Graymer, R.W., Moring, B.C., Saucedo, G.J., Wentworth, C.M., Brabb, E.E., & Knudsen, K.L. (2006, March 6). Geologic Map of the San Francisco Bay Region (Scientific Investigations Map 2918). United States Geological Survey. https://pubs.usgs.gov/sim/2006/2918/ Petersen, M.D., Moschetti, M.P., Powers, P.M., Mueller, C.S., Haller, K.M., Frankel, A.D., Zeng, Y., Rezaeian, S., Harmsen, S.C., Boyd, O.S., Field, N., Chen, R., Rukstales, K.S., Luco, N., Wheeler, R.L., Williams, R.A., & Olsen, A.H. (2014). Documentation for the 2014 Update of the United States National Seismic Hazard Maps (Open-File Report 2014-1091). United States Geological Survey. https://pubs.usgs.gov/of/2014/1091/
Sitar, N., Mikola, R.G., & Candia, G. (2012). Seismically Induced Lateral Earth Pressures on Retaining Structures and Basement Walls. Proceedings of the ASCE GeoCongress 2012 (pp. 1- 24). Geotechnical Special Publication. https://doi.org/10.1061/9780784412138.0013 Thompson, E.M., Wald, D.J., Worden, B., Field, E.H., Luco, N., Petersen, M.D., Powers, P.M., Badie, R. (2016). Shakemap earthquake scenario: Building Seismic Safety Council 2014 Event Set (BSSC2014). United States Geological Survey. https://doi.org/10.5066/F7V122XD United States Geological Survey. (2021). Earthquake Hazards Program: Advanced National Seismic System (ANSS) Comprehensive Catalog of Earthquake Events and Products. United States Department of the Interior. https://earthquake.usgs.gov/earthquakes/search/ Youd, T.L., Idriss, I.M., Andrus, R.D., Arango, I., Castro, G., Christian, J.T., Dobry, R., Liam Finn, W.D., Harder, L.F., Hynes, M.E., Ishihara, K., Koester, J.P., Liao, S.C., Marcuson, W.F., Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K., Seed, R.B., & Stokoe, K.H. (2001). Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils. Journal of DRAFT
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Geotechnical and Geoenvironmental Engineering, 127(4), 297-313. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:10(817) DRAFT
488
FIGURES
DRAFT
489
Date Project No. Figure 1
ROCKRIDGEGEOTECHNICAL
0 3,000 Feet
Approximate scale
1,500
Base map: Google Maps, 2022
SITE
SITE LOCATION MAP
10/10/23 23-2488
401 SAN ANSELMO AVENUE
San Anselmo, California
DRAFT
490
0Approximate scale10 Feet 10/31/23 23-2488 2 San Anselmo, California SITE PLAN Date Project No. Figure 401 SAN ANSELMO AVENUE EXPLANATION Approximate location of boring by Rockridge Geotechnical, Inc., October 2, 2023 B-1 ROCKRIDGE GEOTECHNICAL B-1 DRAFT
491
REGIONAL GEOLOGIC MAP
Approximate scale
2,000
Date Project No. Figure 3
0 4,000 Feet
Geologic contact:
dashed where approximate and dotted
where concealed, queried where uncertain
SITE
Base map: Google Earth with U.S. Geological Survey (USGS), Marin County, 2022.
Qha
Artificial Fill
Mud deposits (late Holocene)
Alluvium (Holocene)
Alluvium (early (Pleistocene)
Alluvium (Pleistocene)
Franciscan Complex sedimentary rocks (Cretaceous)
Franciscan Complex melange (Eocene, Paleocene,
and (or) Late Cretaceous)
Great Valley complex serpentinite (Jurassic)
Franciscan Complex volcanic rocks (Jurassic)
af
Qhym
Qha
Qpa
Qoa
Kfs
fsr
Jsp
Jfv
ROCKRIDGE
GEOTECHNICAL 10/10/23 23-2488
401 SAN ANSELMO AVENUE
San Anselmo, California
Qsl Hillslope Deposits (Quaternary)
DRAFT
492
1906, M7.9
1838, M7.4
1868, M7.0
1989, M6.9
2014, M6.0
San Andreas (SAN)
San Andreas (SAP)
Hayward (HN) Hayward (HS)
San Andreas (SAS)
Monte Vista-Shannon
Calaveras (CN)
Calaveras (CC)
Calaveras (CS)
San Gregorio (North)
San Gregorio (South)
Greenville
Green Valley
Rodgers Creek
Maacama
West Napa Concord
Great Valley (Midland)
Reliz
Great Valley (Orestimba)
1865, M6.5
Symbol Magnitude (Mw)
7.5+
7.0 - 7.4
6.5 - 6.9
6.0 - 6.4
5.0 - 5.9
Historic Earthquake Epicenters
Pre-1900 1900-1970 1971-2021
Date Project No. Figure
REGIONAL FAULT AND HISTORIC
SEISMICITY MAP
20 Miles
Approximate scale
0 10
0 16 32 Kilometers
EXPLANATION
Faults (National Seismic Hazard Model)
ROCKRIDGE
GEOTECHNICAL 4
SITE
10/10/23 23-2488
401 SAN ANSELMO AVENUE
San Anselmo, California
DRAFT
493
k
S lee py
H
ollo w
C ree k
Galli n as Creek
San Rafael Ck
Fairfax
Creek
San Anselm o
Creek
Corte
M adera Ck
R oss
C reek
Larksp u r
Creek
Arr o yo Co
U
S
Highway
1 01
ke Blvd
Kentfield
San Rafa
Ross
Fairfax
Larkspur
San Anselmo
Legend Corte Made
County Boundary
City Boundary
Highways and Major Roads
Streams
Perennial
Intermittent
Ephemeral
Level of Liquefaction Susceptibility*
Water Bodies
Lakes
Lagoons
Very High
High
Moderate
Low
Very Low
Date Project No. Figure 5
0 2 Miles
Approximate scale
1 SITE
LIQUEFACTION SUSCEPTIBILITY MAP
Reference:
Liquefaction Susceptibility Hazards Map 2-11
San Francisco Bay Region, California:
A Digital Database, Open-File Report 00-44,
Online Version 1.0, U.S. Geological Survey, 2000.
ROCKRIDGE
GEOTECHNICAL 10/31/23 23-2488
401 SAN ANSELMO AVENUE
San Anselmo, California
DRAFT
494
APPENDIX A
Log of Boring
DRAFT
495
MC
MC
MC
MC
6 5
4 5
MC
13 7
8 10
MC 15
7 10
12 MC 22
13 13
18 15
5 9
12 11
11 8
8 8
6 6
6 MC 13
6 7
11 MC 20
12 14
14 Sampler
Type
Sample
Blows/ 6"
SPT
N-Value1
DEPTH
(feet)
LITHOLOGY
Boring location:
Date started:
Drilling method:
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 16
17 18
19 20
21 22
23 24
25 26
27 28
29 30
MATERIAL DESCRIPTION
SAMPLES LABORATORY TEST DATA
Figure:
A-1a
PROJECT:
Project No.:
23-2488
Type of
Strength
Test
Confining
Pressure
Lbs/Sq Ft
Shear
Strength
Lbs/Sq Ft
Fines
%
Natural
Moisture
Content,%
Dry
Density
Lbs/Cut Ft
ROCKRIDGE
GEOTECHNICAL
Rope & Cathead Safety Hammer
See Site Plan, Figure 2
10/02/2023 Date finished: 10/02/2023
Hammer weight/drop: 140 lbs./30 inches Hammer type:
7-inch-thick concrete slab
SANDY CLAY (CL)
dark brown, stiff, moist, fine to trace coarse sand
CL
CL
CL
Sampler: Modified California (MC)
PAGE 1 OF 2
Log of Boring B-1
CLAY with SAND (CL)
olive-gray, stiff to very stiff, moist, fine sand
SANDY CLAY (CL)
olive-brown to olive-gray, stiff to very stiff, moist, fine sand SPSC
SAND with CLAY and GRAVEL (SP-SC)
gray-brown, loose, wet, fine to coarse sand, trace fine subrounded gravel
CL
4-inch-diameter solid-stem flight auger
401 SAN ANSELMO AVENUE
San Anselmo, California
(10/02/2023; 4:50 PM)
(10/02/2023; 11:40 AM)
CLAY with SAND (CL)
olive-brown, stiff to very stiff, moist, fine sand
CLAYEY SAND with GRAVEL (SC)
gray, medium dense, wet, fine to coarse sand, trace fine subrounded gravel
SC
CLAY with SAND (CL)
gray, very stiff, wet, fine sand
CLAYEY SAND (SC)
gray, medium dense, wet, fine to medium sand
CLAYEY SAND with GRAVEL (SC)
gray, medium dense, wet, subrounded fine gravel
SC
SC
CL
olive-gray to olive-brown
gray
CLML
C. Velasquez
Stapleton Engineering
& Exploration
Minuteman
Logged by:
Drilled by:
Rig:
CLAY (CL)
dark brown, stiff, moist, trace fine sand
LL = 42, PI = 21; see Appendix B
Particle Size Distribution; see Appendix B
CL
SANDY SILTY CLAY (CL-ML)
olive-gray, medium stiff, wet, fine sand
LL = 27, PI = 7; see Appendix B
Particle Size Distribution; see Appendix B
Particle Size Distribution; see Appendix B
Soil Corrosivity Test; see Appendix B
91 20.9 98
58 25.4 102
11 14.3 123
DRAFT
496
Dry Density
Lbs/Cu Ft
Type of
Strength
Test
Shear Strength
Lbs/Sq Ft
Fines
%
Confining
Pressure
Lbs/Sq Ft
Natural
Moisture
Content, %
Sampler
Type
Sample
Blows/ 6"
SPT
N-Value1
DEPTH
LITHOLOGY
(feet)
31 32
33 34
35 36
37 38
39 40
41 42
43 44
45 46
47 48
49 50
51 52
53 54
55 56
57 58
59 60
MATERIAL DESCRIPTION
SAMPLES LABORATORY TEST DATA
Figure:
A-1b
PROJECT:
Project No.:
PAGE 2 OF 2
Log of Boring B-1
23-2488
ROCKRIDGE
GEOTECHNICAL
401 SAN ANSELMO AVENUE
San Anselmo, California
MC
SAND with CLAY and GRAVEL (SP-SC)
brown, medium dense, wet, fine to coarse sand, fine
subrounded gravel
Boring terminated at a depth of 37.5 feet below
ground surface.
Boring backfilled with cement grout.
Groundwater encountered at 18.5 feet intially, then
17 feet prior to grouting.
CLAY with SAND (CL)
gray, very stiff, wet, fine to medium sand
CL
SPSC
8 13
16 20
MC
10 14
16 21
1 MC blow counts for the last two increments were
converted to SPT N-Values using a factor of 0.7
to account for sampler type and hammer energy.
12 13.5 126
LL = 29, PI = 10; see Appendix B
Particle Size Distribution; see Appendix B
DRAFT
497
CLASSIFICATION CHART
Date Project No. Figure A-2
ROCKRIDGE
GEOTECHNICAL 10/10/23 23-2488
401 SAN ANSELMO AVENUE
San Anselmo, California
Major Divisions Symbols Typical Names
GW
GP
GM
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
Highly Organic Soils PT
UNIFIED SOIL CLASSIFICATION SYSTEM
Well-graded gravels or gravel-sand mixtures, little or no fines Poorly-graded gravels or gravel-sand mixtures, little or no fines Silty gravels, gravel-sand-silt mixtures
Clayey gravels, gravel-sand-clay mixtures
Well-graded sands or gravelly sands, little or no fines Poorly-graded sands or gravelly sands, little or no fines Silty sands, sand-silt mixtures
Inorganic silts and clayey silts of low plasticity, sandy silts, gravelly silts Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, lean clays Organic silts and organic silt-clays of low plasticity
Inorganic silts of high plasticity
Inorganic clays of high plasticity, fat clays
Organic silts and clays of high plasticity
Peat and other highly organic soils
Clayey sands, sand-clay mixtures
Range of Grain Sizes
Grain Size
in Millimeters
U.S. Standard
Sieve Size
Above 12"
12" to 3"
Classification
Boulders
Cobbles
Above 305
305 to 76.2
Silt and Clay Below No. 200 Below 0.075
GRAIN SIZE CHART
SAMPLER TYPE
Coarse-Grained Soils
(more than half of soil > no. 200
sieve size)
Fine -Grained Soils
(more than half of soil
< no. 200 sieve size)
Gravels
(More than half of
coarse fraction >
no. 4 sieve size)
Sands
(More than half of
coarse fraction <
no. 4 sieve size)
Silts and Clays
LL = < 50
Silts and Clays
LL = > 50
Gravel
coarse
fine
3" to No. 4
3" to 3/4"
3/4" to No. 4
No. 4 to No. 200
No. 4 to No. 10
No. 10 to No. 40
No. 40 to No. 200
76.2 to 4.76
76.2 to 19.1
19.1 to 4.76
4.76 to 0.075
4.76 to 2.00
2.00 to 0.420
0.420 to 0.075
Sand
coarse
medium
fine
C Core barrel
CA California split-barrel sampler with 2.5-inch outside diameter and a 1.93-inch inside diameter
D&M Dames & Moore piston sampler using 2.5-inch outside diameter, thin-walled tube
O Osterberg piston sampler using 3.0-inch outside diameter, thin-walled Shelby tube
PT Pitcher tube sampler using 3.0-inch outside diameter, thin-walled Shelby tube
MC Modified California sampler with a 3.0-inch outside
diameter and a 2.43-inch inside diameter
SPT Standard Penetration Test (SPT) split-barrel sampler with a 2.0-inch outside diameter and a 1.38- or 1.5-inch inside diameter (refer to text)
ST Shelby Tube (3.0-inch outside diameter, thin-walled tube) advanced with hydraulic pressure
SAMPLE DESIGNATIONS/SYMBOLS
Sample taken with California or Modified California split-barrel sampler. Darkened area indicates soil recovered
Classification sample taken with Standard Penetration Test sampler Undisturbed sample taken with thin-walled tube
Disturbed sample
Sampling attempted with no recovery
Core sample
Analytical laboratory sample
Sample taken with Direct Push sampler
Sonic
Unstabilized groundwater level
Stabilized groundwater level
DRAFT
498
APPENDIX B
Laboratory Test Results
DRAFT
499
ML or OL
MH or OH
Symbol Source
Natural
M.C. (%)
Liquid
Limit (%)
CL - ML
0 10
20 30
40 50
60 70
0 10 20 30 40 50 60 70 80 90 100 110 120
LIQUID LIMIT (LL)
Description and Classification
% Passing
#200 Sieve
Plasticity
Index (%)
PLASTICITY CHART
Date 10/31/23 Project No. Figure B-1
ROCKRIDGE
GEOTECHNICAL 23-2488
401 SAN ANSELMO AVENUE
San Anselmo, California
PLASTICITY INDEX (PI)
Ref erence:
ASTM D2487-00
B-1 at 3.3 feet
B-1 at 15.8 feet
B-1 at 30.5 feet
CLAY (CL), dark brown
SANDY SILTY CLAY (CL-ML), gray
SAND with CLAY and GRAVEL (SP-SC),
brown
20.9 25.4
13.5 91
58 12
42 27
29 21
7 DRAFT
10 500
SYMBOL SOURCE DEPTH Material Description USCS (ft.)
SOIL DATA
PERCENT FINER
0 10
20 30
40 50
60 70
80 90
100
GRAIN SIZE - mm.
100 10 1 0.1 0.01 0.001
% +3" Coarse
% Gravel
Fine Coarse Medium
% Sand
Fine Silt
% Fines
Clay
0.0 0.0 0.0 0.3 1.0 7.4 91.3
0.0 0.0 0.0 0.9 2.8 38.3 58.0
0.0 5.0 15.5 18.1 33.5 16.5 11.4
0.0 19.1 22.1 15.8 23.5 7.7 11.8 6 in. 3 in. 2 in.
1½ in.
1 in.
¾ in.½ in.3/8 in.#4#10#20
#30#40
#60
#100
#140#200
B-1 3.3' CL
B-1 15.8' CL-ML
B-1 25.3' SP-SC
B-1 30.5' SP-SC
PARTICLE SIZE DISTRIBUTION REPORT
ROCKRIDGE
GEOTECHNICAL 10/31/23 23-2488
401 SAN ANSELMO AVENUE
San Anselmo, California
CLAY, dark brown
SANDY SILTY CLAY, gray
SAND with CLAY and GRAVEL, gray-brown
SAND with CLAY and GRAVEL, brown
Date Project No. Figure B-2
DRAFT
501
S231009A
Method ASTM
G51
ASTM
G200
SM
4500-D
ASTM
D4327
ASTM
D6919
ASTM
D6919
ASTM
D6919
ASTM
D6919
ASTM
D6919
ASTM
D6919
ASTM
D4327
ASTM
D4327
Bore# /
Description
Depth pH Redox Sulfide
S2-
Nitrate
NO3-
Ammonium
NH4+
Lithium
Li+
Sodium
Na+
Potassium
K+
Magnesium
Mg2+
Calcium
Ca2+
Fluoride
F2--
Phosphate
PO43-
(ft) (mg/kg) (wt%) (mg/kg) (wt%) (Ohm-cm) (Ohm-cm) (mV) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg)
62.9 0.0063 12.5 0.0012 4,623 1,742 7.7 147 ND 240.8 3.2 ND 72.3 5.0 30.0 74.5 4.8 2.5 ASTM
G187
ASTM
D4327
ASTM
D4327
Resistivity
As Rec'd | Minimum
Sulfates
SO42-
Chlorides
ClCations and Anions, except Sulfide and Bicarbonate, tested with Ion Chromatography mg/kg = milligrams per kilogram (parts per million) of dry soil weight ND = 0 = Not Detected | NT = Not Tested | Unk = Unknown Chemical Analysis performed on 1:3 Soil-To-Water extract PPM = mg/kg (soil) = mg/L (Liquid)
Note: Sometimes a bad sulfate hit is a contaminated spot. Typical fertilizers are Potassium chloride, ammonium sulfate or ammonium sulfate nitrate (ASN). So this is another reason why testing full corrosion series is good because we then have the data to see if those other ingredients are present meaning the soil sample is just fertilizer-contaminated soil. This can happen often when the soil samples collected are simply surface scoops which is why it's best to dig in a foot, throw away the top and test the deeper stuff. Dairy farms are also notorious for these items.
Date Project No. Figure B-3
B-1: SANDY CLAY (CL) dark brown
Project X REPORT
Corrosion Engineering
Corrosion Control – Soil, Water, Metallurgy Testing Lab 29990 Technology Dr., Suite 13, Murrieta, CA 92563 Tel: 213-928-7213 Fax: 951-226-1720 www.projectxcorrosion.com
ROCKRIDGEGEOTECHNICAL 10/31/23 23-2488
401 SAN ANSELMO AVENUE
San Anselmo, California
1.5 SOIL CORROSIVITY
TEST RESULTS
DRAFT
502
Karen Lamson
Alilam, LLC
407 San Anselmo Ave
San Anselmo, CA 94960
[email protected]
415-328-6046
March 20,2025
San Anselmo Planning Department
Heidi Scoble
Planning Director
Subject: Comprehensive Concerns Regarding Proposed Development at 401 San Anselmo Ave.
Dear Planning Director,
I am writing to formally express my concerns regarding the proposed redevelopment of 401 San Anselmo Ave. As the owner of 407 San Anselmo Ave, which is directly adjacent to the project site, I have significant concerns about the impact of this development, regarding the accuracy of the plans, the impact on my property and tenants, and broader community implications. I also have concerns about the neighboring properties, the town’s character, and public infrastructure.
I have identified multiple issues that require further clarification and review before this project moves forward. This would be for my own knowledge! San Anselmo is known for its historic charm and small-town aesthetic. The proposed development, with its modern design, appears inconsistent with the character of the downtown district. I request that the town consider whether this design aligns with existing architectural guidelines and historic preservation goals.
The most important question is: Do they really need to demo the building to make it useful, Seems kinda extreme?
503
Here are my concerns as a landlord at 407 San Anselmo Ave.
1. Building Height, Fire Safety, and Emergency Access
• The fire department’s comments state that the proposed building is two stories, while the site data on sheet A0.0 states three stories. Which is correct?
• Does the third story require a variance? How will the planning department make the findings for a 3rd story variance? What special circumstances exist that would require the planning department to grant a special privilege? • The roof access area appears to function as a recreational space, with a large glass box and 350 sq. ft. of raised pavers. This suggests significant light pollution and noise impacts on the neighborhood.
• Will Ross Valley Fire Department (RVFD) be able to address an emergency on the proposed third story recreation area? Does their current equipment support a three-story response?
• Where will the fire backflow system be located? How will it affect my property?
• My Building at 407 San Anselmo (Not 409 incorrectly shown on proposed drawings) floor plans and elevations are not shown on drawings depicting the proposed building relationship to 407? This would be helpful in understanding how demolition and rebuilding relate to its adjacent structures instead of appearing like the proposed building stands alone. I would like more clarification so Planning commission is not confused.
2. Wildland-Urban Interface (WUI) and Increased Occupancy Impact • While 401 San Anselmo is technically not within the WUI zone, it directly affects adjacent WUI neighborhoods, such as Pine Street. • Increased occupancy and vehicle traffic from new residential units will impact emergency evacuation routes and overall fire safety. • What mitigation measures will be implemented to address these concerns? 504
3. Parking, Traffic, and Construction Logistics
• Where will construction workers park? How many workers will be onsite daily, and how will this impact nearby businesses and residents? • How will street closures for utility undergrounding, sewer, and water work impact Pine Street and my tenants’ access to my parking lot? • Will PG&E be installing new underground infrastructure? If so, how long will it take?
• The project does not provide any parking, which will force additional cars into nearby residential areas. How does the Planning Department intend to address this?
4. Property Line & Structural Issues
• The site plan shows a 10-inch gap between 401 and 407 parking lot, but no easement is recorded. How does the developer plan to use this gap? • The proposed building roof overhangs my property line. This is a serious concern—how will it be addressed?
• The proposed green wall on the rooftop raises questions:
o How will plants be maintained and watered at 30 feet high in an area that gets extremely hot most of the year?
o Who is responsible for maintenance?
o What happens if plants die, causing an aesthetic or safety issue?
5. Accuracy of Plans and Missing Information
• The cover sheet perspective drawings do not properly depict Town Books, my building, or the new very tall wall in an accurate proportional relationship.
• My property is incorrectly labeled as "409 San Anselmo Ave" on the proposed drawings—this is inaccurate and should be corrected. 505
• No south elevation of the third-story access structure is provided. • The term “Circulation” is used to describe the third-story enclosed space— what does this mean in practical terms?
6. Demolition and Construction Impacts on My Property and Tenants • How will the 30 ft hight shared wall be demolished and rebuilt without access to my parking lot?
• How long is demolition expected to take? I need a realistic timeline that considers how this will affect my tenants and business operations. • What prevents this project from ending up like Jacks Drugs or the Woods project at north end of town? Stalled for years. With plywood walls on sidewalk ets. Should we all find a way to reject the project just to save the developer from Himself.
• What dust, noise, and street closure mitigation measures will be implemented to protect my tenants?
• My spa tenant is extremely concerned about the impact of construction noise, dust, and disruptions to her business.
• My second-floor tenant will also be affected—how does the developer plan to address tenant disruptions?
7. Environmental Considerations & Construction Feasibility • Should a land survey be recorded to ensure accuracy before construction begins? Given the concerns about property lines, I believe this should be required.
• Are there environmental implications with demolishing the existing structure? Have they been studied?
• The construction management plan seems light on realistic details— should I be concerned about how this will be enforced?
8. ADU & Zoning Considerations
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• Does the proposed Accessory Dwelling Unit (ADU) on the ground floor provide the applicant with benefits that are not normally permitted in this zone? If so, what are those benefits?
Request for Review and Consideration
Given these significant concerns, I respectfully ask the Planning Department to:
1. Clarify building height discrepancies and confirm RVFD’s ability to respond to a third-story emergency.
2. Ensure accurate architectural drawings that properly depict the relationship between 401 and 407 San Anselmo Ave.
3. Address parking, traffic, and emergency access impacts in nearby neighborhoods.
4. Provide a clear demolition and construction plan that protects my property and tenants.
5. Correct labeling errors—407 San Anselmo Ave should be properly identified, and the incorrect “409 San Anselmo” reference should be removed.
6. Confirm requirements for undergrounding utilities and provide a realistic timeline for street closures and PG&E work.
7. Explain the environmental impact and construction feasibility measures in place for this project.
I appreciate your time in reviewing these issues. I would like to ask that I be informed of any upcoming public meetings or opportunities for further discussion.
I am the managing partner of Alilam,LLc , but I also have two other partners that have concerns.
Please let me know how I can stay involved in this review process, as this project directly impacts my property, my tenants, and the surrounding community. 507
Sincerely,
Karen Lamson
Alilam, LLC
407 San Anselmo Ave
San Anselmo, CA 94960
508
From: Judy Anderson <[email protected]>
Date: April 17, 2025 at 3:47:54 PM PDT
To: Heidi Scoble <[email protected]>
Subject: 401 San Anselmo Avenue Project
CAUTION: External Sender
I am writing to you about the proposed project at the former Bank of America site. I am the current President of the Friends of the San Anselmo Library (FOSAL). We operate Town Books at 411 San Anselmo Avenue and have concerns about the impact of the project on our business. We are a small nonprofit and all of our earnings go to support the Library. All of us are volunteers. I attended the last meeting when this project was discussed. We are not opposed to the project. It will be an asset to the area.
However, we are concerned about the impact of the demolition and construction on our store, the customers and the volunteers who work at the store. Included in the staff report, Under Exhibit “A” Findings (C) The project will not under the circumstances of the particular case, be detrimental to the health, safety or general welfare of persons residing or working in the neighborhood and will not be detrimental to the public welfare or injurious to property or improvements in the neighborhood.” I believe this refers to the completed Project. The demolition and construction will definitely have a negative impact on us and other tenants in the building. In the Design Review portion of the Findings is stated, “...the Project may temporarily create noise and odors related to construction” which is our main concern. We may very well have to close the store during especially noisy and dusty parts of the project, namely during demolition. I realize that the conditions of approval include a Staging Plan and a Dust Management Plan, but those are not yet available. If we do have to close the store during demolition or construction, we would like to be reimbursed for the financial loss due to any store closures resulting from the Project.
Please share this letter with the Planning Commissioners. Thank you for your consideration.
Judy Anderson, President
Friends of the San Anselmo Library
411 San Anselmo Avenue
San Anselmo, CA 94960
509
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1 Jackson Dobronyi
From: Jesica Brennan <[email protected]>
Sent: Thursday, April 3, 2025 2:30 PM
To: Heidi Scoble; Jackson Dobronyi; Lindsey Klein
Subject: Bank of America Redevelopment Project
CAUTION: External Sender
Hello planning committee!
My name is Jesica, I'm the owner of Sugarfoot Books in downtown San Anselmo and I just wanted to reach out today and offer my support of the redevelopment project of the old Bank of America building.
Laura Allen is a frequent customer here at the bookstore and we spent time discussing her plans for the building. As a San Anselmo resident it really sounds like she has the best interest of the town in mind.
The downtown area would definitely benefit from more retail space in that building, as that is sort of a "dead zone" on the avenue.
I also know the town has been looking to accommodate a growing population and it seems the addition of 4 new apartments upstairs would be very helpful with this endeavor.
I am far enough away that I would not be bothered by construction so I understand that businesses closer might have some objections but I do think it will make a lovely addition to our beautiful downtown when it is finished.
Cheers
Jesica Brennan
Sugarfoot Books Inc
706 San Anselmo Ave.
511
Date: April 6, 2025 at 9:27:11 AM PDT
To: Heidi Scoble <[email protected]>
Subject: Bank of America Bldg. Redevelopment
CAUTION: External Sender
Heidi,
I'm writing to you in support of Michael Day's proposed redevelopment of the former Bank of America building at 401 San Anselmo Ave.
I've known Mike Day for several years and I've always found him to be a kind and generous friend and committed father and husband. He's also a talented business person with a high degree of integrity. As a resident of San Anselmo, I highly respect that Mike has chosen to invest his time and effort in his own town and I'm fully supportive of what he's trying to accomplish.
I've reviewed the plan that Mike has proposed, and see multiple benefits of this project for the Town. In addition to the economic benefits of the commercial space, the residential units in the proposal are helpful in supporting the housing element. At a time when San Anselmo Avenue is showing signs of economic decline, this seems like a perfect project to help revitalize our Downtown.
As with any project, there will be obstacles to overcome in the process. In my view, San Anselmo could find no better partner than Mike Day in finding equitable solutions to move our town forward into the future.
Thank you for your consideration.
My best,
Michael Cerio
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Nancy I Gump, LMFT
407 San Anselmo Ave. Ste. 6
San Anselmo, CA. 2 April, 2025
TO: The San Anselmo Planning Commission
RE: Proposal for 401 San Anselmo Avenue
Dear Planning Comission Members,
I am a tenant in the Courtyard Building located at 407 San Anselmo Avenue. My office is upstairs in the back of the building, where I have a psychotherapy practice. I have had an office in this building since 1991 and have always enjoyed a quiet and peaceful place to do the work I love. I understand that the quiet and peaceful atmosphere of our building will be changing, due to planned demolition and redevelopment of the adjacent building, 401 San Anselmo Avenue. As a business member of long standing in San Anselmo, I am not opposed to building much needed new housing in this location.
However, I do have some strong concerns about the existing plans that have been presented. I hope these concerns can be addressed by your committee at the April 11 meeting and/or as plans for this project proceed.
Concerns About Noise
My office windows look towards Mt. Baldy. Diagonally I see a significant portion of the side of the 401 building, where a second story is proposed. The structure as it currently exists is 30-40 feet from the back wall of my office. A psychotherapy practice will be difficult to conduct in the presence of ongoing construction so close outside my windows. My clients’ experience and my own will be highly impacted by the noise. I would like to know what noise mitigation measures the property owners have planned. I would also like to know the hours of operation for construction work, and I would like to be informed ahead about any highly disturbing procedures such as jack hammering and wrecking balls, etc. I don’t want my business to be ruined by this project.
Concerns About Parking
My landlord, Karen Lamson, provides parking for tenants in our building, and we pay a portion of monthly rent for that privilege. My assigned parking spot butts up against the back of the 401 building. I am concerned about potential damage to my vehicle from construction debris. I understand that my landlord is working with the planning commission to be sure our parking spaces remain available. Nonetheless, with demolition and new construction happening inches away from my parking space (and three others), it is hard to see how damage to my car or others’ cars could be avoided during construction. What reassurance are the owners able to give tenants in my building on this topic? Will they pay for rental vehicles if cars are damaged and need repair - or if time is needed to purchase a new vehicle if a car is ‘totaled?’ 513
Concerns about Demolition of 401 San Anselmo Avenue
I am strongly opposed to the demolition of this historic building, which was constructed 100 years ago in 1925. I understand that it does not have official historic designation, but that doesn’t mean it has no historic value. The building has unique character and brings the Town of San Anselmo a sense of beauty and longevity. I have been told that the reason for demolition is that it would be more costly to make the necessary changes to the existing structure than it would be to destroy it.
Demolishing the building may be financially expedient, but it does have significant costs of a different nature. Losing a landmark that has been in our town for 100 years is one of them. Another cost is that demolition debris can negatively impact the health of anyone in the vicinity. The exemption from a CEQA review does NOT mean there will be no environmental impact.There may be asbestos and/or other toxic materials in the atmosphere, with no certainty as to how long it will take particles to disperse. There is also a cost in human wellbeing to have the noise and destruction that a demolition project entails. It will be difficult, if not impossible for tenants in the Courtyard Building offices (407- 411 San Anselmo Ave) to continue their work during demolition. There will be financial losses, and losses to the wellbeing of clients who patronize these businesses.
There are ways to retrofit and otherwise support an old structure so that it can serve a new purpose. I would like the planning commission to consider requiring the new owners to present an alternative plan that does not require demolition of the 401 building. If they are saying it is not financially feasible, I believe they should provide evidence of that fact. If the commission decides to allow demolition, I would like the owners to be required to provide the landlord and tenants in my building with the following:
1. Dates and times for each aspect of demolition
2. Information about the presence of ANY toxic chemical, including asbestos, and what the plans are for appropriate removal. (And please inform us how they will know about the presence of toxic materials if there is no environmental review?)
3. A plan for minimizing the noise and disruption to businesses in our building
4. Notification ahead of time about any potential loss of electricity, water, etc.
Thank you to the members of the Planning Commission for your consideration of my concerns.
Respectfully,
Nancy I Gump
Licensed Marriage & Family Therapist
407 San Anselmo Ave. Ste 6
415 630-0897
514
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1 Jackson Dobronyi
From: Sam Jelley <[email protected]>
Sent: Friday, April 4, 2025 7:04 PM
To: Heidi Scoble; Jackson Dobronyi; Lindsey Klein
Cc: [email protected]
Subject: Support for 401, San Anselmo Ave - Former Bank of America Redevelopment Project
CAUTION: External Sender
Dear Heidi, Jackson & Lindsey,
I hope this message finds you well. I am writing to express my strong support for the proposed redevelopment plans for the former Bank of America Building at 401, San Anselmo Ave to incorporate both retail and residential spaces. This project presents an exciting opportunity for our community, and I believe it will bring numerous benefits to the area.
By introducing new retail spaces, we can attract businesses that will provide goods and services, fostering growth and job creation within our town. Additionally, the inclusion of residential units will contribute to a vibrant, mixed-use area that encourages foot traffic and community engagement.
The design and vision behind the redevelopment appear thoughtful and well-planned, ensuring that it aligns with the character of our town. This kind of development will also provide more housing options, addressing the growing demand for residential space in our area.
I am confident that the project will ultimately enhance the quality of life for current residents while attracting new families, businesses, and visitors to our town. I encourage you to support this redevelopment initiative and look forward to seeing its positive impact.
Thank you for your time and consideration.
Sincerely,
Samantha Jelley
www.neatlybay.com
516
Karen Lamson
Alilam, LLC
407-411 San Anselmo Ave
April 1, 2025
Heidi Scoble
San Anselmo Planning Commission,
Subject: Concerns Regarding Demolition and Redevelopment of 401 San Anselmo Ave Dear Planning Commission,
Thank you so much for taking the time to meet with me and Bill yesterday. I just want to make sure that my major concern for 407-411 Building gets noted. My desire would be not to have the developer tear down the building. To see if there is any other way to build out the building without demolishing the current building.
As the owner of the adjacent property at 407-411 San Anselmo Ave, my building is directly connected to the existing structure at 401 San Anselmo Ave on one side, while my parking lot borders the other side of the property. Given this close proximity, I have significant concerns about the impact of the demolition and rebuilding process on my property.
Concerns Regarding the Demolition of 401 San Anselmo Ave
1. Structural Integrity of Adjacent Building (407-411 San Anselmo Ave) o Since my building and 401 San Anselmo Ave are directly attached, what measures will be in place to prevent structural damage, such as cracks or foundational shifts, during demolition?
o Will a structural assessment be conducted before and after demolition to ensure my building remains undamaged?
2. Protection of My Parking Lot
o My parking lot directly borders 401 San Anselmo Ave. How does the developer plan to conduct demolition and construction without accessing, encroaching on, or using my parking lot in any capacity?
517
o Will protective barriers or fencing be installed to prevent falling debris or dust from affecting my lot?
o What steps will be taken to ensure my parking spaces remain fully accessible and undisturbed during construction?
3. Construction Staging & Access
o How will the developer be able to demolish and rebuild without encroaching on my building and parking lot.
o Where will construction materials and equipment be staged to ensure they do not spill over onto my property?
4. Debris Containment and Cleanup
o What specific measures will be taken to prevent dust, debris, and construction materials from impacting my building and parking lot?
o Who will be responsible for immediate cleanup if debris ends up on my property?
5. Utility Disruptions
o Given that the buildings are connected, could the demolition impact shared utilities such as water, sewer, or electrical lines?
o What contingency plans are in place to prevent service disruptions to my property?
6. Liability and Insurance Coverage
o In the event of accidental damage to my building or parking lot, what liability protections and insurance coverage will the developer have in place? o Will there be a bond or escrow fund established to cover potential repairs caused by demolition-related issues?
Request for Review & Consideration
I respectfully request that the Planning Department require the developer to submit a detailed demolition and construction plan addressing these concerns before granting final approval.
This plan should specifically outline:
• Methods for protecting my property during demolition. • How all work will be contained within their property lines. 518
• Steps to minimize disruptions to neighboring businesses and property owners. • I will ask the town for temporary fencing to keep all contracts and workers out of my parking lot.
I appreciate your time in reviewing these concerns and look forward to your response regarding how these matters will be addressed. I will be attending the Meeting on April 7th.
Sincerely,
Karen Lamson
Alilam, LLC
407-411 San Anselmo Ave
[email protected]
415-328-6046
519
1 Jackson Dobronyi
From: Elizabeth Lasnier <[email protected]> Sent: Sunday, April 6, 2025 9:01 PM
To: Lindsey Klein; Heidi Scoble; Jackson Dobronyi
Subject: Bank of America - building project
CAUTION: External Sender
Hi,
I had a chance to review the project plan for the Bank of America building with my neighbor Laura Allen. It seems like her and Michael's proposal is a great way to repurpose the old bank - their project will bring a muchneeded refresh to the empty building on the corner. I am not excited about a demolition and the ensuing rebuild; however, it is a relatively short period of time, and the end result will be well worth it. My kids and I would much prefer to walk past beautiful shops, and they would also welcome new friends to walk to school with once the residences are occupied.
As a San Anselmo resident of over 15 years, I look forward to that side of town experiencing some revitalization that Laura's project will surely bring.
Thanks,
Elizabeth Lasnier
197 Tunstead Ave, San Anselmo
520
1 Jackson Dobronyi
From: Chris Mancini <[email protected]>
Sent: Monday, April 7, 2025 8:44 AM
To: Heidi Scoble; Jackson Dobronyi; Lindsey Klein
Subject: RE: BofA Building Project Corner of San Anselmo & Pine CAUTION: External Sender
Lindsey, Jackson, and Heidi,
My wife and I are longtime residence of San Anselmo. We’ve raised three children here and love our town.
We’ve reviewed the project plans for the old Bank of America building and want to share our input. While we understand folks living near, or abutting the project will be apprehensive about the process, ultimately all will benefit from the finished project.
The town will have a well designed building matching the look and feel of San Anselmo ave, we will not see the building decay empty for years, and ultimately the finished product will contribute more vibrant, improved retail space. As a bonus it will enable more people to become part of our town.
We are in support of the project and trust you will make the best decision for our town. If you have any follow up questions please don’t hesitate to give me a call.
Thank you for your time and consideration,
Chris and Stacie Mancini
415-250-0407
521
1 Jackson Dobronyi
From: Anna Psaila <[email protected]>
Sent: Monday, April 7, 2025 11:11 AM
To: Heidi Scoble; Jackson Dobronyi; Lindsey Klein
Cc: Laura Allen
Subject: 401 San Anselmo Ave.
Follow Up Flag: Follow up
Flag Status: Flagged
CAUTION: External Sender
To Whom It May Concern,
My name is Anna Psaila, I am a San Anselmo Business owner of 25 years and a Marin native. I Recently met with Laura Allen to talk over the plans at 401 San Anselmo Ave.
She explained the project details and listened to any concerns I had. I would like to express my support in this project. I Believe turning this Vacated Building into a beautiful and Safe environment for New Retailers and community Members will be a WELCOME addition to our downtown. It looks to be modern and up to date while still keeping our San Anselmo Charm that is so important to all of us. We need more Driven And professional people such as Laura Allen to be encouraged and supported when it comes to updating our buildings.
Thank You For your support in this.
Sincerely,
Anna Psaila
--
The linked image cannot be displayed. The file may have been moved, renamed, or deleted. Verify that the link points to the correct file and location.
Thank You for your support!
www.seesaw4kids.com
SeeSaw Children's Consignment
722 San Anselmo Ave.
San Anselmo, CA. 94960
415-295-7979
We Are OPEN EVERYDAY 10-5
Consignment Drop Off is by appointment only.
522
523
1 Jackson Dobronyi
From: Emily Robb <[email protected]>
Sent: Monday, April 7, 2025 10:46 AM
To: Heidi Scoble; Jackson Dobronyi; Lindsey Klein
Subject: Bank Of America Redevelopment Project
Follow Up Flag: Follow up
Flag Status: Flagged
CAUTION: External Sender
Good Morning Heidi, Jackson, and Lindsey,
I am writing to you this morning in support of the Bank Of America Redevelopment Project in San Anselmo. I have reviewed the plans and considered the impact this development will have on our community. The updating of the building will enhance the appearance of downtown and show the city's commitment to allowing the town to modernize and update. The space will not only provide beautiful space for business but also create residential units that are much needed. As a residential real estate agent, I see this benefiting the city and its economy.
A rooftop space would be beneficial and appealing to any future occupants of the residential spaces. Having a private space to enjoy in a multi-unit building will increase desirability and overall value.
San Anselmo has the best downtown of all Marin County towns. The update to this building will only amplify the town's aesthetic and support the downtown business community.
I appreciate you considering my support, and I look forward to seeing this amazing building in the future.
Sincerely,
Emily Robb
415-535-8893
524
1 Jackson Dobronyi
From: Jan Springer <[email protected]>
Sent: Saturday, April 5, 2025 9:38 PM
To: Heidi Scoble; Jackson Dobronyi; Lindsey Klein
Cc: Laura Allen; William Wu
Subject: Support for Redevelopment of 401 San Anselmo Avenue CAUTION: External Sender
To: San Anselmo Planning Officials
From: Will and Jan Wu, 2 Foothill Road, San Anselmo
This letter is in full support of the redevelopment of the property located at 401 San Anselmo Avenue. This property has been a vacant eyesore for far too long and needs to be approved for a vibrant new multi-use building in the heart of San Anselmo.
The plans submitted by Rhino One, LLC include a tasteful redesign of the existing, high traffic corner with two retail suites on the first floor, three residential units on the second floor and added greenery throughout to soften the lines. The airy design compliments the downtown landscape and adds much needed additional housing to San Anselmo.
Rhino One, LLC owners, Laura Allen and Michael Day, are active San Anselmo residents with a young family.
They have strong roots in the community and are invested in improving our town. They are proven leaders in the redevelopment space and are willing to work with neighboring businesses to mitigate the impact while under construction.
As San Anselmo residents for the past eight years, we have witnessed the revitalization in the downtown. While we are thrilled with the new businesses that have come in and the updates to existing structures, we have heard far too many horror stories from owners regarding their experience working with the Town's planning department. We personally experienced this with our home remodel and hope the Town is addressing the department's shortfalls.
In closing, we ask that plans for redevelopment of 401 San Anselmo Avenue be considered and approved in a timely manner. We wholeheartedly support the work of Rhino One, LLC and are available to discuss further should you have any questions.
Best,
Jan and Will Wu
2 Foothill Road
773.456.0178
525
1 TOWN OF SAN ANSELMO
PLANNING COMMISSION STAFF REPORT
For the meeting of April 7, 2025
Agenda Item 6.A
Date: April 7, 2025
To: Chair Strauss and Members of the Planning Commission From: Lindsey Klein, Senior Planner
Jackson Dobronyi, Assistant Planner
Subject: PRO2024-0048, Mixed-Use Development at 401 San Anselmo Avenue (APN 007-251-22) Recommendation
The Planning Commission review the merits of the Project, continue the item to the next regular Planning Commission meeting, and direct staff to prepare the appropriate resolution to either approve or deny the Project, with conditions of project approval as applicable.
Property Information
Project Address: 401 San Anselmo Avenue
Property Owner/Applicant: Rhino One, LLC
Assessor’s Parcel No.: 007-251-22
Zoning District: C-2, Downtown Commercial
General Plan: CC, Central Commercial
FIRM Flood Zone: AE Flood Zone (1% annual chance of flooding) Permits Required
• Demolition Permit required pursuant to Town of San Anselmo Municipal Code Section 10-3.2102 to allow for the demolition of the existing commercial building. • Grading Permit required pursuant to Town of San Anselmo Municipal Code Section 9-18.08 to allow for the combined excavation, grade, or fill of more than 100 cubic yards of material. • Design Review required pursuant to Town of San Anselmo Municipal Code Section 10-3.1505(a)(1) to allow for a new building within C-2 Zoning District. 526
2 • Conditional Use Permit pursuant to Town of San Anselmo Municipal Code Section 10-6.305 to allow for an exception to the maximum allowed floor area for a one-bedroom Accessory Dwelling Unit (ADU).
• Variance pursuant to Town of San Anselmo Municipal Code Section 10-3.1401 to allow for a threestory building, where a maximum of two stories are permitted within the C-2 Zoning District. • Variance pursuant to Town of San Anselmo Municipal Code Section 10-3.1401 to allow for a 37- foot tall building, where a maximum building height of 30 feet is permitted within the C-2 Zoning District.
Project Data
Existing Proposed Code
Zoning C-2, Downtown Commercial No Change N/A
General Plan CC, Central Commercial No Change N/A
Flood Zone
AE Flood Zone (1% annual
chance of flooding)
No Change N/A
Residential Density 0 3 (plus an ADU)*
Minimum: 2
Maximum: 3
Lot Size (sq. ft.) 4,543 No Change N/A
Floor Area (sq. ft) 4,955 8,850 9,086
Adjusted Floor Area
Ratio (%) 109% 195% 200%
Setbacks
Front: 0’
Interior Side: 0’
Street Side: 0’
Rear: 10”
Front: 0’
Interior Side: 0’
Street Side: 0’
Rear: 0’
Front: 0’
Interior Side: 0’
Street Side: 0’
Rear: 0’
On-Site Parking 0 0 0 **
Stories 2 3 2
Maximum Height Above
Average Existing Grade 28’ 11” 37’ 30'
Grading Quantities (cubic
yards or “CY”) N/A
Cut: 131 CY
Fill: 92 CY
Off-Haul: 39 CY
Combined: 131 CY
N/A
* An ADU in this Zoning District is considered to be an accessory residential use that is consistent with the General Plan and does not exceed the allowable density or expand or intensify the residential use. ** See the Parking subsection of the Staff Analysis and Discussion below.
Project Description
The Project includes the following components:
• Demolition of the existing two-story commercial bank building. 527
3 • Site grading of 131 cubic yards (CY) of material related to the proposed foundations and site leveling.
• Construction of a new three-story 8,850-square-foot mixed-use building, which includes:
o Two ground-floor commercial spaces with frontage along San Anselmo Avenue. One space would be 1,376 square feet; one space would be 774 square feet. o A one-bedroom, 1,173-square-foot ADU, located on the ground floor with frontage and access along Pine Street.
o Three residential units located on the second story, including a 1,177-square-foot threebedroom unit (Unit 1), a 1,099-square-foot two-bedroom unit (Unit 2), and a 1,404- square-foot three-bedroom unit (Unit 3).
o A third-story rooftop deck that is approximately 1,800 square feet in size. o Rooftop solar arrays, exterior mechanical/HVAC equipment, and metal trellis with climbing vines on the third story.
o Interior stairs, circulation, utility, and mechanical rooms totaling 1,848 square feet, split across the three stories.
• Proposed exterior finishes and materials including “Cloud White” stucco siding, “Big Band” tan stucco siding, black-clad windows and doors, “Norfolk Black” brick veneer, light cream cast stone trim, “Natural Copper” clad bay window roof and fascia, “Redland Clay” terra cotta roof tiles, “Greenscreen” metal trellises with climbing vines on a sound proofing wall, and “Tanglewood” canvas awnings.
(This area is intentionally blank. Staff Report continues on next page) 528
4 Figure 1 – Existing Site Plan
Figure 2 – Proposed Site Plan
Pine St.
Pine St.
529
5 Figures 3 – Proposed Floor Plans
Ground Floor Plan
Second Floor Plan
Pine St.
Pine St.
530
6 Third Floor / Roof Plan
(This area is intentionally blank. Staff Report continues on next page) Pine St.
531
7 Figures 3 – Proposed Elevations
East (Front) Elevation, San Anselmo Ave Frontage
West (Rear) Elevation
Red dashed line indicates the outline of the existing structure to be demolished. 532
8 North (Interior Side) Elevation
Red dashed line indicates the outline of the existing structure to be demolished.
Blue dashed line indicates the outline of the adjacent structure at 407 San Anselmo Ave.
San Anselmo Ave
South (Street Side) Elevation, Facing Pine St.
533
9 Project Site and Background
The Project site is a portion of Lot 20 of the Linda Vista Tract and is approximately 4,543 square feet in size. The lot is relatively flat with a 1 percent average slope. The lot is located within the 100-year flood plain, or AE Flood Zone, meaning there is a 1 percent annual chance of flooding.
The site was initially developed circa 1926. The building was owned and operated by the Home Savings and Commercial Bank but was soon after sold to the Bank of Italy. In 1928, the Bank of Italy merged with Bank of America of Los Angeles, and in 1930, changed its name to Bank of America. In 1946, additions were built on the north and west sides of the structure, creating the building envelope that exists today.
Only exterior modifications to the building have occurred since 1946. In the 1960s, the three large arched windows on the Pine Street façade were removed, and their openings were infilled. A Historic Resource Evaluation (HRE) was prepared by Ver Planck Historic Preservation Consulting and dated April 30, 2024 to assess whether a property qualifies as a historic resource based on its architectural, cultural, or historical significance, typically to inform planning and preservation decisions (see Attachment 2). The HRE indicates that the Project site does not appear eligible for the California Register of Historical Resources under any of the eligibility criteria, in part due to extensive alterations that have taken place since the building was originally constructed.
The parcels along San Anselmo Avenue between Tunstead Avenue and Pine Street are zoned C-2, Downtown Commercial, and their uses are a mix of retail and office uses. The Project site is a corner lot, bound by commercial uses to the north, a private parking lot to the west, San Anselmo Avenue to the east, and Pine Street to the south. Across these roads, there are more commercial uses to the east and a public parking lot to the south.
An aerial view of the Project site, outlined in blue, is shown in Figure 5, and Figure 6 shows the street views of the Project site.
Figure 5 – Aerial Site View
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10 Figures 6
Street View from San Anselmo Avenue Facing West
Street View from Pine Street Facing North
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11 Street View from Pine Street Facing Northeast
Staff Analysis and Discussion
General Plan Consistency
Land Use Consistency
The Project has a General Plan land use designation of Central Commercial (CC), which is found along portions of San Anselmo Avenue and Sir Francis Drake Boulevard between the Hub and Tunstead Avenue and is expected to be the retail core of the community. Commercial enterprises are expected to provide continuity of commercial frontage and attractive areas for pedestrian movement. Parking is not anticipated onsite but would be provided in public or common parking lots within walking distance of all downtown businesses.
Residential uses in the form of multi-family housing are allowed in the Central Commercial district.
Residential uses can be provided for in a single structure or maybe mixed with commercial activity in a single structure; the ground floor of every building should be utilized for commercial or commercialrelated uses. The General Plan notes, however, that the Town may consider the entire use concept for a building before determining the appropriate use of the ground floor. Buildings within the Central Commercial district could have a FAR of up to 2.0. The heights of buildings in this category are to be compatible with surrounding buildings but shall not exceed 30 feet in height.1 The Project proposes a three-story, 37-foot tall mixed-use building totaling 8,850 square feet. The building would feature commercial spaces along San Anselmo Avenue, a ground-floor ADU accessible from Pine Street, three second-story residential units, and a roof deck and mechanical room located on 1 Height limits were added to the General Plan land use designations per Town Council Reso No. 3074 (1988). At that time, the height limit in the Central Commercial district was 35 feet. Town Council Reso. No. 3137-A (1991) amended this height limit to 30 feet.
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12 the third story. As currently proposed, the Project is inconsistent with the General Plan because the proposed building exceeds the maximum height allowed in the Central Commercial district. 2 The Town is updating the General Plan, including the land use descriptions. Given State housing mandates and current best practices, staff recommend removing height restrictions from all land use descriptions through a General Plan Amendment. Therefore, staff suggest that the proposed Project could be phased to move forward to achieve consistency with the General Plan. Staff request Planning Commission direction on the following options:
• Approach 1: The Planning Commission would conditionally approve the project as proposed with a Variance to exceed the maximum building height. The condition of approval would require a General Plan Amendment to remove height restrictions from all land use descriptions prior to issuance of a building permit. This approach would allow the project to enter the building permit phase while the General Plan is undergoing a targeted amendment.
• Approach 2: This approach would include two phases. In Phase One, the Planning Commission would conditionally approve the project to reduce the building height to 30 feet (or less) to comply with the General Plan.3In Phase Two, following adoption of a targeted General Plan Amendment that removes height restrictions from all land use descriptions, the proposed Project may return to seek approval for a Variance to exceed the 30-foot height limit. This could be included as a condition of project approval, if directed by the Planning Commission.
Alternatively, the height restrictions will likely be removed from the land use descriptions as part of the General Plan Update. If preferred, the Planning Commission may opt to forgo a separate General Plan Amendment, and a height increase could occur upon adoption of an updated General Plan, anticipated in 2026.
Goal and Policy Consistency
Staff suggest that the proposed Project conforms with the following General Plan goals and policies:
• Land Use Goal 1: The small town character, scale, and pace of life in San Anselmo shall be preserved, as shall the Town's close connection with the natural beauty of its setting. • Land Use Goal 2: Maintain the economic viability of the Town's commercial core. • Land Use Goal 3: New developments shall be integrated harmoniously into San Anselmo's existing neighborhoods and commercial areas.
• Land Use Goal 5: Accommodate the housing needs of a socially and economically diverse population. • Land Use Policy 2.2: New development will be required to preserve some of the natural and cultural characteristics of their respective development sites.
• Land Use Policy 3.3: Mixed residential and housing opportunity development is most appropriate where sites have few environmental constraints, and have adequate facilities, such as water, sewer, transit, and access to commercial services.
2 The Demolition Permit, Grading Permit, and Design Review each have a requisite finding that the project is consistent with the General Plan. As a result, any inconsistency with the General Plan (e.g., height inconsistency) would prevent approval of these related permits as well.
3 This approach ensures the project is consistent with the height limits in the General Plan. This also allows the proposed project to meet the General Plan consistency finding required for approval of the Demolition Permit, Grading Permit, and Design Review. In addition, the proposed project would no longer be required to obtain Variances. 537
13 • Land Use Policy 3.4: Mixed residential and housing opportunity development is also appropriate along major traffic arterials and adjacent to commercial and office areas. • Land Use Policy 4.2: Retail commercial is best suited for the central area. • Land Use Policy 11.1: New development, including rehabilitation and expansion projects, shall be of a scale, intensity, and design that integrates with the existing character of the surrounding neighborhood.
• Land Use Policy 16.2: To only allow development within the 100-year floodplain which is consistent with the Town's adopted Protection of Flood Hazard Areas and Water Course Ordinance.
Zoning Ordinance Compliance
The Project site is zoned Downtown Commercial (C-2), which is applied to existing commercial areas along San Anselmo Avenue and Sir Francis Drake Boulevard between The Hub and Ross Avenue, which form the Town's central business district. The intent of this district is to develop primary attractors, which draw the majority of their customers from outside the community, and satellite businesses, which rely upon pedestrian movements generated by the primary attractors Mixed uses are also allowed within the District; however, offices and residential uses are encouraged to locate above the ground floor to preserve the District's primary purpose of providing for commercial activities. An ADU in this Zoning District is considered to be an accessory residential use that is consistent with the General Plan and does not exceed the allowable density or expand or intensify the residential use. The District has a density range of between 13 and 20 residential units per acre and a maximum floor area ratio of 2.0.
The Project proposes a three-story, 37-foot tall mixed-use building totally 8,850 square feet. The building would feature commercial spaces along San Anselmo Avenue, a ground-floor ADU accessible from Pine Street, three second-story residential units, and a roof deck and mechanical room located on the third story. Apart from the Variances discussed in this Staff Report, the Project complies with the development standards of the C-2 Zoning District (including floor area and setbacks).
Parking
The Town’s Parking Standards Table (Table 5A) in Title 10, Chapter 3, Article 5, Parking and Loading Regulations, of the San Anselmo Municipal Code requires:
• One on-site parking space for each studio, one-bedroom, or two-bedroom living unit within a multifamily residential or mixed-use building;
• One and a half on-site parking spaces for each three-bedroom (or greater) living unit within a multifamily residential or mixed-use building; and
• One on-site parking space for each 500 gross square feet of a commercial building’s floor area.
The Town’s parking regulations are superseded by State law. AB 2097 prohibits local agencies from imposing minimum parking requirements on development projects within one-half mile of public transit.
AB 2553, signed into law in September 2024, expanded the definition of public transit to include intersections of major bus routes with service intervals of 20 minutes or less during peak commute times.
Pursuant to AB 2097 and AB 2553, the bus stop located at the intersection of Sir Francis Drake Boulevard and Center Boulevard, known as the Hub, is defined as a public transit stop. The Project site is located 538
14 within one-half mile of the Hub. Given State law, no parking requirements may be imposed on the Project or any new development within one-half mile of the Hub.
Section 3-5.1207, All-Night Parking Prohibited Without Permit, of the Municipal Code prohibits overnight parking on any street in San Anselmo between the hours of 2:00 AM and 6:00 AM unless a valid, current Overnight Street Parking Permit has been issued and is affixed to the vehicle. Resident Overnight Parking Permits are issued by the Central Marin Police Authority upon a demonstration of hardship in accordance with the Municipal Code.
Affordable Housing
The Project is subject to Town’s Inclusionary Housing Ordinance (San Anselmo Municipal Code Title 10, Chapter 21, Affordable Housing), adopted in August 2023 through Town Council Resolutions 4497 and 4498 and Ordinance 1178. The purpose of the Ordinance is to expand the supply of affordable housing in San Anselmo by requiring that new residential and non-residential development projects contribute to housing opportunities for a broad range of households with varying income levels.
Under these regulations, residential developments of two or more units to contribute to the Town’s affordable housing stock. Project applicants proposing two or more units may choose to:
• Construct affordable housing units as part of the proposed project; • Pay the in-lieu fee identified in the Town’s adopted Fee Schedule; or • Propose an alternative compliance method subject to Town approval.4 The Project applicant has elected to satisfy the Inclusionary Housing Ordinance by paying the in-lieu fee.
Development in the Flood Zone
The Project Site is located within the 100-year flood plain, or AE Flood Zone. Title 7, Chapter 11, Protection of Flood Hazard Area, in the San Anselmo Municipal Code regulates development in Federal Emergency Management Agency (FEMA) Flood Zones. The Town requires that all new construction of residential structures in the AE Flood Zone shall have the lowest floor elevated to 1 foot above the base flood elevation (BFE). Furthermore, the Town requires that nonresidential construction shall be similarly elevated or meet an alternative means of compliance as certified by the Floodplain Administrator (i.e., the Public Works Director).5 The Project would be conditioned to comply with these requirements.6 Demolition and Construction Management Plan
The Project includes a preliminary Demolition and Construction Management Plan (DCMP) to reduce construction related impacts to the surrounding neighborhood. As shown in Attachments 2 and 4, the DCMP addresses construction impacts related to parking, vehicle traffic, and pedestrian circulation; the 4 For more information on these options, refer to Resolutions 4497 and 4498 and the Town Inclusionary Housing webpage. 5 Alternative means of compliance, as indicated in Section 7-11.501, would include that the nonresidential construction: be floodproofed, together with attendant utility and sanitary facilities, below the elevation recommended under Section 7-
11.501(c)(1), so that the structure is watertight with walls substantially impermeable to the passage of water; have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and be certified by a registered civil engineer or architect that the standards of Section 7-11.501(c)(2)(i) and (ii) are satisfied. 6 The applicant has provided two surveys within their Project Plans (see Attachment 1). It is important to note that these surveys provide different elevations for the site, as they are based on different topographic datums. 539
15 construction schedule; construction staging; and encroachment permits. In particular, the proposed DCMP includes the following provisions:
• Parking: Limited on-site parking (2 spaces) and potential use of the Pine Street Public Lot (up to 3 spaces, with permits from the Public Works Department). No long-term construction-related parking would be allowed in the public right-of-way adjacent to the site; off-site parking may be required for additional needs.
• Pedestrian Circulation: A minimum 4-foot clear pedestrian walkway along the sidewalks shall be maintained throughout construction. Temporary sidewalk closures, managed by an on-site safety manager, may be necessary during demolition and material deliveries. Encroachment permits would be required for all sidewalk closures.
• Traffic Impacts: Vehicular access to the construction site would be limited to a single driveway created on Pine Street. Utility undergrounding, as required by the Town, may result in temporary road closures along Pine Street. Traffic control measures (i.e., signage, delineators, flag persons) proposed to minimize disruptions during construction deliveries. Encroachment permits would be required for road closures.
• Property Lines: Temporary construction fencing proposed to protect pedestrians and adjacent properties, and prevent unauthorized access to private property. • Project Schedule: Demolition (including hazardous material abatement) is anticipated to take one month; site preparation and construction would take approximately 14 months. In total, construction is expected to occur over 16 months.
• Debris Box Location: A debris box would be required to be located on-site and outside of the public right-of-way.
The Department of Public Works (DPW) has reviewed the Project and found the DCMP to provide a sufficient level of detail at this stage. During the Building Permit phase, DPW would require a complete DCMP with precise information including, but not limited to deliveries/road closures, sidewalk closures, construction hours (as they relate to noise attenuation in the area), the construction schedule, and ADAcompliant vehicular access to the site, to be reviewed and approved prior to the issuance of any building, demolition, or encroachment permits.
Staff recommends that the Planning Commission consider the following as conditions of project approval to minimize any potential demolition and construction related impacts:
• Temporary accessible pedestrian paths of travel are provided during sidewalk closures to allow for continuous, safe pedestrian access and minimize disruptions to downtown circulation. • No construction-related parking shall be allowed within the public right-of-way adjacent to the project site, and additional parking shall be secured on private property. This would reduce vehicle parking congestion at the project site and ensure parking remains available for downtown customers. • A licensed structural engineer shall be present on-site during demolition to monitor the demolition process to ensure that the demolition work and construction of the new building does not impact the structural integrity of adjacent structures.
• An on-site preconstruction meeting is required with the Town, property owner/applicant, contractor, the owner and tenants of 407-411 San Anselmo Avenue, and associated parties to discuss the DCMP and clarify procedures for debris clean up, site access, and construction hours. • The Project applicant shall designate the adjacent property at 407-411 San Anselmo Ave, APN 007- 251-23, and the Town of San Anselmo as additional insureds on their construction policy, to the 540
16 extent permitted by law, protecting adjacent property owners and the Town from potential liability or damages related to construction activities.
• The Project applicant shall secure a construction bond in the amount of 125% of the Project’s valuation, issued by a surety company authorized to operate in the State of California. This would safeguard against project abandonment or financial insolvency, ensuring timely Project completion. • Temporary fencing between 401 San Anselmo Ave, 407-411 San Anselmo Ave, and the parking lot to the west (at APN 007-251-23), shall be required to mitigate the spread of construction debris and prevent unauthorized access to private property.
• The building wall separating 401 San Anselmo Ave and 407-411 San Anselmo Ave shall be surveyed and staked by a licensed surveyor prior to demolition of 401 San Anselmo Ave to verify property boundaries and prevent damage or encroachment on adjacent structures during demolition and construction.
• Materials shall be staged in an off-site location and transferred to the site, as needed, to minimize encroachment into the downtown public right-of-way on San Anselmo Avenue and Pine Street. • Water shall be used to suppress dust during demolition activities, minimizing airborne particulate matter.
• Noise: The Project shall be required to adhere to Title 4, Chapter 7, Loud Noises, of the Municipal Code. In addition, the Project shall be required to adhere to the following:
o Noise-generating demolition activities, such as heavy equipment operation and material removal, shall be restricted to 8:30 AM to 4:30 PM. No demolition shall occur on weekends or holidays observed by the Town.
o All demolition equipment shall be equipped with properly functioning mufflers and noise attenuation devices.
o The contractor shall provide written notification to all adjacent property owners and residents at least 14 days prior to the commencement of demolition activities, detailing the Project schedule and anticipated noise levels.
Demolition Permit
Pursuant to the San Anselmo Municipal Code Title 10, Chapter 3, Article 21, Demolition Permit, the purpose of the Demolition Permit is to consider retention of community character related to the historic, architectural, cultural, and/or aesthetic importance of a structure, minimized disturbance and hazard to the neighborhood and the community, and maintenance of housing units to further the goals of the General Plan Housing Element.
As previously summarized in this staff report, a Demolition Permit is required to demolish the existing commercial building. To approve or conditionally approve the Demolition Permit, the Commission must make the findings for the Demolition Permit in Section 10-3.2104 of the San Anselmo Municipal Code, listed in italics below.
(1) The demolition will not remove from the neighborhood or Town, nor adversely affect, a building of historical, architectural, cultural, or aesthetic value. (2) The project is consistent with the San Anselmo General Plan. (3) The project will not, under the circumstances of the particular case, be detrimental to the health, safety or general welfare of persons residing or working in the neighborhood and will not be detrimental to the public welfare or injurious to property or improvements in the neighborhood. 541
17 (4) The granting or denying of a demolition permit for the demolition of structures may also be subject to the following findings based on substantial evidence as determined by the Planning Commission or Town Council.
(a) Failure to approve a demolition permit will cause immediate and substantial hardship because of the conditions peculiar to a particular structure, and such hardship has not been created by an act of the owner in anticipation of action under this chapter. Examples of hardship include health and safety hazards that cause the building to be unsafe. Personal, family, financing difficulties, loss of prospective profits and neighboring violations are not justifiable hardships. (b) It is necessary to reveal previous architectural features covered up, such features that would be functionally and aesthetically compatible with the existing improvements and the natural elements of the area.
Given proposed Project characteristics (i.e., high-traffic pedestrian area, no on-site parking, adjacency to other retail, personal services, and offices uses), Town staff request Planning Commission direction on whether Finding number 3 can be met, with or without conditions of project approval. 7 A list of
potential conditions of approval – beyond the provisions identified in the proposed DCMP – has been provided at the end of this staff report for Commission consideration.
Grading Permit
Pursuant to the San Anselmo Municipal Code Title 9, Chapter 18, Excavation, Grading, and Erosion Control, the purpose of the Grading Permit is to establish controls on excavation, grading, and fill within the Town. The controls are established for reasons of safety, erosion control, sound, soil engineering practice, aesthetics, environmental protection, and water quality protection.
As previously summarized in this staff report, a Grading Permit is required to allow for the combined excavation, grade, or fill of more than 100 cubic yards of material. The Project proposes approximately 131 cubic yards of earthwork. To approve or conditionally approve the Grading Permit, the Planning Commission must determine whether the Project is in conformance with the required Grading Permit Findings in Section 9-18.08(c) of the San Anselmo Municipal Code, listed below in italics:
(1) The health, welfare and safety of the public will not be adversely affected; (2) Adjacent properties are adequately protected by project investigation and design from geologic hazards as a result of the work;
(3) Adjacent properties are adequately protected by project design from drainage and erosion problems as a result of the work;
(4) The amount of excavation, grading, or fill proposed is not more than is required to allow the property owner reasonably beneficial use of his or her property; (5) The visual and scenic enjoyment of the area by others will not be unreasonably adversely affected by the project;
(6) Natural landscaping will not be removed by the project more than is necessary and that any removed vegetation will be replanted in a timely manner;
7 The Demolition Permit’s Finding number 2 requires that the project be consistent with the General Plan. Consequently, any inconsistency with the General Plan (e.g., height inconsistency) prevents the approval of a Demolition Permit as well.
See the proposed phased approach in the General Plan Consistency section to ensure consistency with this Demolition Permit finding.
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18 (7) The time of year during which construction will take place is such that work will not result in excessive siltation from storm runoff nor prolonged exposure of unstable excavated slopes; (8) The proposed excavation, grading, or fill does not violate the Town's General Plan or zoning Codes; (9) Sufficient erosion control measures will be employed to offset any impact by the proposed excavation, grading, or fill.
Upon review of the Project, and as evidenced by the Geotechnical Investigation Report (see Attachment 3), Town staff suggest that most of the Grading Permit findings can be supported.8 However, Town staff request Planning Commission's direction on whether Finding number 1 can be met, with or without conditions of project approval. In particular, Town staff request that the Commission consider whether the DCMP provides sufficient information at this stage to ensure that demolition and construction would not result in detrimental impacts to the health, welfare, and safety of persons residing or working in the surrounding area.
Conditional Use Permit
Pursuant to the San Anselmo Municipal Code Title 10, Chapter 3, Article 13, Conditional Use Permit, the purpose of a Conditional Use Permit is to allow for the review of a specific use or uses to ensure that the use is compatible with surrounding land uses and to allow, if necessary, the imposition of conditions.
As previously summarized in this staff report, a Conditional Use Permit is required to allow for an exception to the maximum floor area allowed for a one-bedroom ADU. To approve the Conditional Use Permit, the Planning Commission must determine whether the Project is in conformance with the required Conditional Use Permit Finding in Section 10-3.1305 of the San Anselmo Municipal Code, listed below in italics.
(1) The establishment, maintenance, or operation of the use will not, under the circumstances of the particular case, be detrimental to the health, safety, peace, morals, comfort, and general welfare of persons residing or working in the neighborhood of the proposed use, or be detrimental or injurious to property or improvements in the neighborhood or to the general welfare of the Town.
Upon review of the Project, staff suggest that the requisite finding can be achieved because the Project would not impose unsafe conditions on persons residing or working in the neighborhood for the following reasons:
• The Project would be required to comply with the California Building Standards Code and California Fire Code.
• The ADU would be designed to be accessible, with features to ensure the safety of all occupants including those with mobility challenges.
• The ADU is a land use consistent with the General Plan.
Variances
Pursuant to Title 10, Chapter 3, Article 14, Variance, of the San Anselmo Municipal Code, the purpose of a Variance is to allow for deviations from development standards set forth in the Municipal Code. As 8 The Grading Permit’s Finding number 8 requires that the project be consistent with the General Plan. Consequently, any inconsistency with the General Plan (e.g., height inconsistency) prevents the approval of a Grading Permit as well. See the proposed phased approach in the General Plan Consistency section to ensure consistency with this Grading Permit finding. 543
19 previously summarized in this staff report, Variances are requested for relief from the maximum building height and story requirements to allow for:
• A 37-foot tall building, where a maximum building height of 30 feet is permitted within the C-2 Zoning District; and
• A three-story building, where a maximum of two stories are permitted within the C-2 Zoning District.
To approve or conditionally approve the Variances, the Planning Commission must determine whether the Project is in conformance with the required Variance findings in Section 10-3.1405 of the San Anselmo Municipal Code, listed below in italics:
(1) Due to special circumstances applicable to the property, including size, shape, topography, location, or surroundings, the strict application of the controlling zoning ordinance or regulation deprives the property of privileges enjoyed by other property in the vicinity and under an identical zoning classification, and the granting of the variance will not constitute a grant of special privileges inconsistent with the limitations upon other properties in the vicinity and zone in which such property is situated; and
(2) The granting of the variance, under the circumstances of the particular case, will not materially affect adversely the health or safety of persons residing or working in the neighborhood of the property of the applicant and will not be materially detrimental to the public welfare or injurious to property or improvements in such neighborhood.
Town staff request Planning Commission direction on whether Finding number 1 can be met for approval of both Variances.
Design Review
Pursuant to the San Anselmo Municipal Code Title 10, Chapter 3, Article 15, Design Review, the purpose of Design Review is to minimize adverse effects of poor or inappropriate exterior design of improvements to real property by providing for the review of the design of certain buildings and improvements constructed in the town. As previously summarized in this staff report, Design Review is required for the construction of a new building within the C-2 Zoning District.
To approve or conditionally approve the Design Review, the Commission must make the findings for Design Review in Section 10-3.1506 of the San Anselmo Municipal Code, listed below in italics:
(a) Commercial, Professional, and Residential R-3 (four (4) or more units, churches, convalescent homes). (1) Is functionally and aesthetically compatible with the existing improvements and the natural elements in the surrounding area;
(2) Provides for protection against noise, odors, and other factors which may make the environment less desirable;
(3) Will not tend to cause the surrounding area to depreciate materially in appearance or value or otherwise discourage occupancy, investment, or orderly development in such area; (4) Will not create unnecessary traffic hazards due to congestion, distraction of motorists, or other factors and provides for satisfactory access by emergency vehicles and personnel; (5) Will not adversely affect the health or safety of persons using the improvement or endanger property located in the surrounding area; and
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20 (6) Is consistent with the Town General Plan.
Town staff suggest that many of the requisite Design Review findings can be met. The Project proposes a more modern design that deviates from the older character of the adjacent properties, but the Town seeks to encourage creativity and variety in design pursuant to Section 10-3.1501 of the Municipal Code.
Therefore, Town staff suggest that the proposed modern architecture, while visually different from adjacent developed property, has the capacity to functionally complement the area and enhance the architectural quality of an existing neighborhood, while retaining aesthetic compatibility.
Staff is seeking direction from the Planning Commission regarding whether Finding number 1, Finding number 2, and Finding number 6 can be met.9 As mentioned in a public comment, is unclear at this project stage where all required above-ground utilities would be installed (i.e., within the building interior, on the building exterior, or in the public right-of-way). Staff ask the Planning Commission to consider whether the project application provides sufficient information about the proposed utilities to determine that the project would be functionally and aesthetically compatible with the existing improvements and the natural elements in the surrounding area. As described in the DCMP subsection, staff are concerned regarding the potential impacts of the construction noise related to Finding number 2 and ask the Planning Commission to consider whether the project provides for sufficient protection against noise, odors, and other factors which may make the environment less desirable, with or without conditions of project approval.
CEQA Determination
The Project is Categorically Exempt from the requirement for the preparation of environmental documents pursuant to Title 14 of the California Code of Regulations (CCR), Chapter 3, Article 19, Sections 15303 under a Class 3 categorical exemption for “New Construction or Conversion of Small Structures” (14 CCR § 15303). This exemption applies as the Project involves a mixed-use development located in an urbanized area, totaling no more than four residential units, with a total floor area of less than 10,000 square feet. No exception set forth in Section 15300.2 of the CEQA Guidelines applies to the Project, including, but not limited to, Subsection (a), which relates to impacts on environmental resources (previously developed site, and no sensitive species have been identified in the surrounding area); (b), which relates to cumulative impacts (developed neighborhood; no other projects are proposed in the nearby area and if any are received, each would have a construction management plan reviewed by the Building and Public Works Departments); Subsection (c), which relates to unusual circumstances (the construction is proposed on a previously disturbed site and method of construction is not out of character with this type of construction); or Subsection (f), which relates to historical resources (the Project site is not historic).
Public Notice and Comments
A notice was mailed to all property owners within 300 feet of the site and posted in three places. Staff has received one written comment as of the distribution of this report (see Attachment 5). Concerns raised in the written comment include:
• Increased building height
9 The Design Review Finding number 6 requires that the project be consistent with the General Plan. Consequently, any inconsistency with the General Plan (e.g., height inconsistency) prevents the approval of Design Review as well. See the proposed phased approach in the General Plan Consistency section to ensure consistency with this Design Review finding. 545
21 • Adequate fire safety and emergency access
• Impacts on parking and traffic patterns
• Location of new utilities in the public right-of-way and impacts to the construction timeline • Unclear property boundaries
• Construction impacts on parking, traffic, road closures, dust, noise, and utility undergrounding • Logistics of building demolition and timeline given proximity to neighboring structures • Inaccurate labeling in the Project plans
Planning Commission Direction
Direction is sought from the Planning Commission on the following Project components:
• Is the Planning Commission amenable to a phased approach to project approval as it relates to General Plan consistency? If yes:
• Is the Planning Commission interested in a targeted General Plan Amendment? • Can Demolition Permit Finding number 3 and Grading Permit Finding number 1 be made? If not:
• What additional information in the DCMP is needed to render decisions? Information could include, but is not limited to:
• Street closure information
• Noise and dust reduction strategies related to demolition • Construction parking plan
• Does the Planning Commission recommend any conditions of project approval, including any of the following options?
• Temporary accessible pedestrian paths of travel shall be provided during sidewalk closures. • No construction-related parking shall be allowed within the public right-of-way adjacent to the project site, and additional parking shall be secured on private property. • A structural engineer shall be present on-site during demolition to monitor the demolition process and ensure that the demolition work does not impact the structural integrity of adjacent structures.
• An on-site preconstruction meeting is required with the Town, property owner/applicant, contractor, the owner and tenants of 407-411 San Anselmo Avenue, and associated parties to discuss the DCMP and clarify procedures for debris clean up, site access, and construction hours.
• The Project applicant shall designate the adjacent property at 407-411 San Anselmo Ave, APN 007-251-23, and the Town of San Anselmo as additional insureds on their construction policy, to the extent permitted by law.
• The Project applicant shall secure a construction bond in the amount of 125% of the Project’s valuation, issued by a surety company authorized to operate in the State of California, to ensure Project completion.
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22 • Temporary fencing between 401 San Anselmo Ave, 407-411 San Anselmo Ave, and the parking lot to the west (at APN 007-251-23), shall be required to mitigate the spread of construction debris and prevent unauthorized access to private property. • The building wall separating 401 San Anselmo Ave and 407-411 San Anselmo Ave shall be surveyed and staked by a licensed surveyor prior to demolition of 401 San Anselmo Ave. • Materials shall be staged in an off-site location and transferred to the site, as needed. • Water shall be used to suppress dust during demolition activities, minimizing airborne particulate matter.
• Noise: The Project shall be required to adhere to Title 4, Chapter 7, Loud Noises, of the Municipal Code. In addition, the Project shall be required to adhere to the following:
• Noise-generating demolition activities, such as heavy equipment operation and material removal, shall be restricted to 8:30 AM to 4:30 PM. No demolition shall occur on weekends or holidays observed by the Town.
• All demolition equipment shall be equipped with properly functioning mufflers and noise attenuation devices.
• The contractor shall provide written notification to all adjacent property owners and residents at least 14 days prior to the commencement of demolition activities, detailing the Project schedule and anticipated noise levels.
• Can Design Review Findings number 1 and number 2 be made, given the project application and the proposed conditions of approval?
• Can Variance Finding number 1 be made for both requested exceptions to the height limits? • Does the Planning Commission have any other comments or suggestions? Attachments
Attachment 1 – Project Plans
Attachment 2 – Historic Resource Evaluation
Attachment 3 – Geotechnical Investigation
Attachment 4 – Project Narrative
Attachment 5 – Comment Letter - Lamson
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1 MINUTES
TOWN OF SAN ANSELMO PLANNING COMMISSION
Monday, April 7, 2025
This meeting was conducted in person and via Zoom.
Commissioners Jennifer Asselstine
Present: Zack Koblick de Leon
Kim Pipkin
Gary Smith
Peter Strauss (Chair)
Thomas Tunny
Commissioners Tim Heiman (Vice Chair)
Absent
Staff Present: Planning Director Heidi Scoble
Senior Planner Lindsey Klein
Assistant Planner Jackson Dobronyi
Assistant Public Works Director Scott Schneider
Assistant Civil Engineer Will Messinger
1. Call to Order
Chair Strauss opened the meeting at 7:00 p.m.
2. Open Time for Public Expression
There were no comments.
3. Planning Directors Report
• She discussed the new link to e-comments.
• The General Plan Advisory Committee (GPAC) met on April 3rd and will be meeting again on April 10th.
• The Town Council will discuss the undergrounding of utilities at tomorrow night’s meeting.
• The Economic Development Committee will meet on April 9th. • There will be an Earth Day Festival at Wade Thomas School on April 19th. • The Town is recruiting for a Building Official.
• At the April 22nd meeting the Council will adopt a Proclamation declaring May as Small Business Month.
4. Approval of Minutes
A. Approve minutes from the March 3, 2025 meetings.
M/s, Asselstine/Tunny, motion to approve the March 3, 2025 minutes as submitted.
Ayes: Asselstine, Pipkin, Tunny, Chair Strauss
Abstain: Koblick de Leon, Smith
Absent: Heiman
5. Business Items
A. 11 Sunnyside Avenue (Right-of-Way Abandonment) The proposed project is exempt 548
2 from CEQA under CEQA Guidelines Section 15305
Assistant Engineer Messinger presented a staff report and a PowerPoint presentation. Staff answered questions from the Commission regarding what is meant by “abandonment”; how much land is involved; if the retaining was recently built and if a Building Permit was required; if a right-of-way abandonment would be required prior to a Building Permit; if there would be an increase in the Floor Area Ratio as a result of the transfer of land; why this property owner is the only one seeking the abandonment.
Chair Strauss opened the meeting to public comments.
There were no comments.
Chair Strauss closed the meeting to public comments.
Commissioner Smith provided the following comments:
• This is a reasonable approach for transferring the property. • He understood the need for the retaining wall. It is a benefit to the Town.
M/s, Koblick de Leon/Pipkin, motion to approve the 11 Sunnyside Avenue Right-of-Way Abandonment.
Ayes: Asselstine, Koblick de Leon, Pipkin, Smith, Tunny, Chair Strauss
Absent: Heiman
Chair Strauss stated there was a 10-day appeal period.
6. Public Hearings
A. Demolition Permit, Grading Permit, Conditional Use Permit, Variances, and Design Review at 401 San Anselmo Avenue, APN 007-251-22, Demolition Permit for the demolition of an existing commercial structure, a Grading Permit for 131 cubic yards of earthwork, a Conditional Use Permit to allow an Accessory Dwelling Unit (ADU) to exceed 1,000 square feet, Variances to allow for a three-story building, where only two stories is permitted, and to allow for a 37-foot tall building, where a maximum building height of 30 feet is permitted, and Design Review for the construction of a new three-story, 8,850 square-foot mixed-use building. The proposed project is categorically exempt from CEQA pursuant to 14 CCR Section 15303 Assistant Planner Dobronyi presented a staff report and a PowerPoint presentation. Staff answered questions from the Commission regarding whether a Height Variance was issued for the adjacent building; if clerestory windows could be installed on the ground floor of the west elevation; if there are any assurances that the Town would not have any issues should the developer have financial issues after the building is demolished; the height of the US Bank building; regulations in the C3 and C2 Districts; if the Housing Element contains height restrictions; in-lieu fees; Inclusionary Housing requirements; if all the units would be market rate; the three options cited in the staff report; a targeted General Plan Amendment; the Conditions of Approval cited in the staff report; issues of property lines and shared building walls; how affordable housing rents would be calculated and how much tenants would be paying; the Regional Housing Needs Assessment (RHNA) and the percentage of affordable units required; why the project is considered three stories; if the signage is being reviewed tonight; if only the penthouse exceeds the 30-foot height limit; it the trellis would be cantilevered off of the parapet; if there are other three-story buildings in the C2 District; if the penthouse would serve only as access; how the opportunity for ten units was lost; if the Municipal Code includes provisions for a Special Use District or Planned Unit Development 549
3 District; if the demolition could be restricted to hours that are more congenial to the adjacent businesses; when the determination is made with respect to the depth of the foundation (Building Permit, third-party plan check); if the parapet is lower and the penthouse is higher than the building next door; if there will be noise abatement and visual screening for any mechanical units.
Chair Strauss opened the meeting to public comments.
Ms. Laura Allen, applicant, made the following comments:
• She gave a PowerPoint presentation.
• The prior project consisted of ten residential units and two commercial units. • They were asked to reduce the unit count to four units to comply with density regulations.
• This is a concrete and rebar building with very few windows- working with the current envelope would be nearly impossible.
• Retrofitting would require extensive structural modifications. • She displayed the current design and the first and second floor plans. • The proposed building height is 31 feet to the top of the parapet and 37 feet at the top of the mechanical roof. The neighboring building is 38 feet high. • The height of the existing building is just short of 28 feet. • They are retaining some of the design elements including a re-creation of the arched windows.
• There will be two and three bedroom units.
• She displayed the roof deck design.
• They have incorporated sustainable design elements and exceed the Title 24 requirements.
• She displayed renderings of the ground floor commercial space and the live/work unit (ADU).
• She stated downsizing to four units makes BMR housing a challenge. • They are not required to provide on-site parking due to the proximity to public transit. • They have identified several practical approaches to mitigate parking issues. • She discussed the Construction Management Plan.
• Her insurance agent told her a Construction Bond is not generally required for this type of project. She asked the Commission to forgo this requirement. • The demolition will take less than 30 days, and the structural engineer does not need to be on site. The general contractor should be sufficient. • They are providing a substantial community benefit.
Ms. Allen and her consultants answered questions from the Commission regarding whether the prior plan had only one commercial space; if the corner commercial space could be housing; the allowable density; if the topic of a Density Bonus was ever discussed; why there is no “set back” window on the lower floor; the anticipated completion; the design of the building relative to the adjacent building; if they considered a waterproofing aspect between the buildings; if the lot has been surveyed and whether another survey should be done during demolition; the design of the front entrance arch and the black brick.
Stewart, architect, made the following comments:
• They can get the light to penetrate the ground floor. This is a lifestyle choice, and the square footage is more important.
• He discussed construction and zero lot line buildings. 550
4 Mr. Carl Deal made the following comments:
• There is no local historic designation for this building because there is no mechanism for that to take place.
• It is up to the Commission to provide this historic protection. • He discussed Page 5, 6, & 7 of the Historic Resource Evaluation and the photographs of the neighboring buildings.
• He asked if there was a use for the existing building that would “pencil out”.
Mr. Brendon Quinn made the following comments:
• He supports the proposed mixed use development.
• It would support the businesses and provide housing units in the downtown corridor.
Mr. Benedetto Chico, owner of the San Anselmo Inn, made the following comments:
• He wished the applicants the best of luck.
• Demolition will have a strong negative impact, and he is concerned about the mitigations. They need to be very clear.
• Traffic will be an issue with large trucks coming to the project.
Ms. Karen Lampson, owner of 407-411 San Anselmo Avenue, made the following comments:
• She has long-term tenants.
• She is concerned about the demolition.
• The project is in close proximity to her building, and she is concerned about impacts from the construction.
A tenant at 411 San Anselmo Avenue made the following comment:
• She is concerned about the impact on the day spa.
Ms. Nancy Gump made the following comment:
• She has a psychotherapy practice at 407 San Anselmo Avenue and is concerned about the construction impacts.
Mr. Jeff Kroot made the following comments:
• Windows can be on the property line if they are against the street. • He feels that the downtown is “under attack”- there are some boarded up buildings. • He is concerned about demolishing this building and then nothing happens. • He discussed historic buildings in the downtown area.
Ms. Teri Moore, Pine Street, made the following comment:
• She asked if the demolition of the inside of the bank was done with a permit and if a Haz Mat team did the work.
Nicole made the following comments:
• She had concerns about the destruction of an historic building, building more luxury housing in San Anselmo, and detouring foot traffic during construction.
A resident on Pine Street made the following comment:
• She asked the Commission to consider the impacts to parking during construction.
Chair Strauss closed the meeting to public comments.
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5 Commissioner Tunny provided the following comments:
• He is generally in support of the project. He supported Option #1. • This is a small property, and the density choices were made through the Housing Element process.
• He appreciated the comments made by the public.
• The project strikes a balance of interests, needs, and priorities of the community. • The unique character of San Anselmo should be maintained. • The project is well designed and provides important housing. • He agreed with the concerns regarding the businesses at 407-411 San Anselmo Avenue.
• He wants to support the Variances, but it might be difficult to make the Findings. • The applicant might think about a way to redo the penthouse, so it is not a third story. • The staff report was excellent.
Commissioner Smith provided the following comments:
• He agreed with the comments made by Commissioner Tunny. • He would like to minimize the impacts on the adjoining businesses. • A Construction Bond should be required.
Commissioner Koblick de Leon provided the following comments:
• The applicants are attempting to work with the Town and the neighbors. • He is disappointed about the reduction of units and the removal of the BMR units. • He is considering the benefits to the Town, the addition of units, the RHNA numbers, and the beauty of the renderings.
• Option #1 is the way to go.
• The neighbors need to be protected from damages as much as possible.
Commissioner Pipkin provided the following comments:
• She has concerns about the affordable housing piece. The goal should be to increase housing at all levels of affordability.
• The housing crisis will not be solved by being timid. • Option #1 is the best solution.
• This is a small project and will not result in major disruption. • Professional demolition and construction companies can get this done. • She would prefer more units.
• She supports the project and would like to see it go forward.
Planning Director Scoble read following comments provided by Commissioner Heiman:
• He referred to one of the Conditions of Approval and thought a structural engineer is not necessary and a licensed general contractor could do the job. • He could support a phased approach (1) with respect to the height. • He referred to the DCMP and stated covered pedestrian access along San Anselmo Avenue should be provided with construction site access from Pine Avenue only. • Design Review Findings #1 and #2 can be made.
• He is ok with the height limit and third story variance.
Commissioner Asselstine provided the following comments:
• The lower unit is lacking in natural light.
• She is disappointed that they are looking at granting a third story variance but not getting a third story of housing. This is a missed opportunity. 552
6 • She agreed with the comments made by Mr. Kroot- it would be a disaster to lose some of the buildings in Town.
• She did not want the approval for three stories on this site to “open the flood gates”. • Parking needs to be addressed.
• A contractor can be present during demolition- it does not have to be a structural engineer.
• She would like more information about adding another property to the insurance and whether requiring a bond would be a burden.
• Noise is a huge issue and will not go away 100%. There are mitigations. There should be good communication between neighbors.
• The proposed design for the front façade (archway and brick) is distracting.
Chair Strauss provided the following comments:
• He agreed with the comments made by the other Commissioners. • He supports the project but was not sure about the variance for the third story. • He agreed with Mr. Deal’s comments about the historic district. • This building has been altered quite a bit.
• Enforcement of mitigations will be very important.
• There will need to be thoughtful consideration given to the adjacent businesses. • The Variance Findings for the 31 feet and 37 feet could be made.
M/s, Tunny/Koblick de Leon, motion to continue this item to the next meeting to bring back a resolution of approval for the required entitlements and additional Conditions of Approval that incorporate the comments made by the Commission tonight.
Ayes: Asselstine, Koblick de Leon, Pipkin, Smith, Tunny, Chair Strauss
Absent: Heiman
7. Future Agenda Items and/or Commissioner Reports
Commissioner Asselstine stated she would like to see the following item on an upcoming agenda: General Plan Advisory Committee Goals.
Commissioner Koblick de Leon announced that he resigned from the Commission, and this is his last meeting. The Commission wished him well in his future endeavors.
8. Adjournment- Chair Strauss adjourned the meeting at 10:17 p.m. The next meeting is scheduled for Monday, April 21, 2025 at 7:00 p.m.
Respectfully submitted,
Toni DeFrancis
Recording Secretary
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1 TOWN OF SAN ANSELMO
PLANNING COMMISSION STAFF MEMORANDUM
For the meeting of April 21, 2025
Agenda Item 5.A
Date: April 21, 2025
To: Chair Strauss and Members of the Planning Commission From: Lindsey Klein, Senior Planner
Jackson Dobronyi, Assistant Planner
Subject: PRO2024-0048, Mixed-Use Development at 401 San Anselmo Avenue (APN 007-251-22) Recommendation
The Planning Commission adopt a resolution approving Project No. PRO2024-00248, for a Demolition Permit to allow for the demolition of the existing two-story commercial building, a Grading Permit to allow for the combined excavation, grade, or fill of 131 cubic yards of material, a Conditional Use Permit allow for an exception to the maximum allowed floor area for a one-bedroom Accessory Dwelling Unit (ADU), a Variance to allow for a three-story building, where a maximum of two stories are permitted, a Variance to allow for a 37-foot tall building, where a maximum building height of 30 feet is permitted, and Design Review for a new 8,850-square-foot, three-story, mixed-use building, subject to the findings and conditions within the resolution (see Attachment 1).
Property Information
Project Address: 401 San Anselmo Avenue
Property Owner/Applicant: Rhino One, LLC
Assessor’s Parcel No.: 007-251-22
Zoning District: C-2, Downtown Commercial
General Plan: CC, Central Commercial
FIRM Flood Zone: AE Flood Zone (1% annual chance of flooding) 554
2 Discussion
On April 7, 2025, the Planning Commission conducted a public hearing for the consideration of the following permits:
• Demolition Permit required pursuant to Town of San Anselmo Municipal Code Section 10-3.2102 to allow for the demolition of the existing commercial building. • Grading Permit required pursuant to Town of San Anselmo Municipal Code Section 9-18.08 to allow for the combined excavation, grade, or fill of more than 100 cubic yards of material. • Conditional Use Permit pursuant to Town of San Anselmo Municipal Code Section 10-6.305 to allow for an exception to the maximum allowed floor area for a one-bedroom Accessory Dwelling Unit (ADU).
• Variance pursuant to Town of San Anselmo Municipal Code Section 10-3.1401 to allow for a threestory building, where a maximum of two stories are permitted within the C-2 Zoning District. • Variance pursuant to Town of San Anselmo Municipal Code Section 10-3.1401 to allow for a 37- foot tall building, where a maximum building height of 30 feet is permitted within the C-2 Zoning District.
• Design Review required pursuant to Town of San Anselmo Municipal Code Section 10-3.1505(a)(1) to allow for a new building within C-2 Zoning District.
At the public hearing, Planning Commissioners expressed support for the project and approved a motion to continue the item to the April 21 Planning Commission meeting. The Commission directed staff to prepare a resolution of approval, findings for all the Project’s required entitlements, and conditions of approval that respond to the Commissioner’s comments raised during the hearing. In particular, staff was asked to ensure that the demolition and construction management plan includes the following measures:
• Accessible pedestrian access along San Anselmo Avenue and Pine Street, to ensure safe and continuous pedestrian circulation.
• Parking plan to reduce congestion and downtown parking, particularly within the public right-of-way on San Anselmo Avenue and Pine Street.
• Temporary Fencing along the property lines to protect the Town’s infrastructure and adjacent buildings.
• Staging plan for materials storage and deliveries, to minimize encroachment into the public right-ofway on San Anselmo Avenue and Pine Street. • Dust management plan, to suppress airborne dust during demolition and construction.
In response to the direction given at the April 7, 2025, public hearing, staff has prepared a resolution approving the demolition of the existing two-story commercial building, 131 cubic yards of earthwork, and the construction of a new 8,850-square-foot, 37-foot tall, three-story, mixed-use building, subject to the findings and conditions of approval within the resolution.
Attachments
Attachment 1 – Draft Resolution, Findings, and Conditions of Approval Attachment 2 – Staff Report from April 7, 2025, Planning Commission Meeting Attachment 3 – Letter from Applicant, dated April 14, 2025 555
1 MINUTES
TOWN OF SAN ANSELMO PLANNING COMMISSION
Monday, April 21, 2025
This meeting was conducted in person and via Zoom.
Commissioners Jennifer Asselstine
Present: Tim Heiman (Vice Chair)
Kim Pipkin
Gary Smith
Peter Strauss (Chair)
Thomas Tunny
Staff Present: Planning Director Heidi Scoble
Senior Planner Lindsey Klein
Assistant Planner Jackson Dobronyi
1. Call to Order
Chair Strauss opened the meeting at 7:00 p.m.
Chair Strauss announced that agenda item #5D will be continued to the May 5th meeting.
2. Open Time for Public Expression
There were no comments.
3. Planning Directors Report
• There will be an Appreciation Event for Board, Commission, and Committee members on May 2nd.
4. Approval of Minutes
A. None
5. Public Hearings
A. Demolition Permit, Grading Permit, Conditional Use Permit, Variances, and Design Review at 401 San Anselmo Avenue, APN 007-251-22, Demolition Permit for the demolition of an existing commercial structure, a Grading Permit for 131 cubic yards of earthwork, a Conditional Use Permit to allow an Accessory Dwelling Unit (ADU) to exceed 1,000 square feet, Variances to allow for a three-story building, where only two stories are permitted, and to allow for a 37-foot tall building, where a maximum building height of 30 feet is permitted, and Design Review for the construction of a new three-story, 8,850 square-foot mixed-use building The proposed project is categorically exempt from CEQA pursuant to 14 CCR Section 15303 Assistant Planner Dobronyi presented a staff report and a PowerPoint presentation. Staff answered questions from the Commission regarding the ADU and the characteristics that qualify it to be an ADU; the Height Variance and why it was necessary to modify the General Plan; the intent of Exhibit H, #13, Phased Performance Guarantee, and if there is precedence for this Condition of Approval; if the Town was aware of the typical cost of a Construction Bond; the change in the language of the Construction Bond; the Variance Findings.
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2 Chair Strauss opened the meeting to public comments.
Ms. Laura Allen, applicant, made the following comment:
• She would be happy to answer any questions.
Mr. Stewart Welty, architect, made the following comments:
• There is a COP Plan that discusses the beginning stages of the project along with rules. • He discussed the proposed precautionary measures.
• Demolition would start at the west end and proceed from the inside out. • The façade would be removed last.
• There will be a minimal amount of off-haul.
• There will be compaction and reworking of the soil due to the building’s location in the Flood Zone.
• Supplies will be stored off-site and brought in when needed. • There will be a debris box on-site and it would be removed when needed. • They are focusing on sustainability and waste management.
Mr. Carl Deal made the following comments:
• His wife has an office at 407 San Anselmo Avenue and parks her car twelve inches away from the wall that will be demolished.
• He asked about mitigations during demolition.
Ms. Judy Anderson made the following comments:
• She is concerned about the impacts to the Town Books parking lot and access to the store for customers and the workers/volunteers.
• She asked how long the demolition would take so they could make plans.
A resident made the following comments:
• She is wondering if she would need to move her business- it cannot be done in a construction zone.
• She asked about the construction of a sound wall.
• She would like more information about work hours, how long the project will take, etc.
Chair Strauss closed the meeting to public comments.
Staff and Mr. Welty responded to the questions from the Commission and the public regarding the fence and blankets that will be used to mitigate noise; the overall duration of the construction; if there is a mechanism for the applicant to rent parking stalls from a public lot.
Commissioner Pipkin provided the following comment:
• There could be numerous construction projects happening at the same time in this area including the Jack’s Pharmacy location.
M/s, Asselstine/Tunny, motion to approve the Resolution presented by staff including all the Conditions of Approval and the minor language changes suggested by Commissioner Tunny.
Ayes: Asselstine, Heiman, Pipkin, Smith, Tunny, Chair Strauss Chair Strauss stated there was a 10-day appeal period.
557
3 5. Public Hearings
B . Consider Adoption of Ordinance Amendments to Title 10 “Planning and Zoning”, Chapters 2, 3, and 4 of the Municipal Code and the Zoning Map for Housing Element Implementation and Compliance with State Law. The proposed Ordinance is exempt from CEQA pursuant to Guidelines Section 15301, 15303, and 15061(b)(3) Senior Planner Klein presented a staff report and a PowerPoint presentation. Staff answered questions from the Commission regarding the percentage of actions that have been accomplished, what is remaining, and if there is a prioritization; Attachment #2, Exhibit A and #3.
Chair Strauss opened the meeting to public comments.
There were no comments.
Chair Strauss closed the meeting to public comments.
Commissioner Heiman provided the following comments:
• There should be consistency when referring to the Affordable Housing Overlay (AHO). • The section in Exhibit A regarding lot line adjustments is circuitous and backwards. He suggested some re-wording.
• He supports the adoption of the Ordinance.
Commissioner Tunny provided the following comment:
• The modifications make sense.
M/s, Heiman/Pipkin, motion to recommend that the Council Adopt the Ordinance Amendments to Title 10 “Planning and Zoning”, Chapters 2, 3, and 4 of the Municipal Code and the Zoning Map for Housing Element Implementation and Compliance with State Law with the modifications discussed.
Ayes: Asselstine, Heiman, Pipkin, Smith, Tunny, Chair Strauss
5. Public Hearings
C. Consideration of the Adoption of a Resolution Recommending the Town Council Nominate Sorich Ranch Park and Faude Park as Two Priority Conservation Areas and Authorize Submission to the Association of Bay Area Governments (ABAG) The proposed Resolution is not subject to CEQA pursuant to CEQA Guidelines Section 15060(c)(3)
Senior Planner Klein presented a staff report and a PowerPoint presentation. Staff answered questions from the Commission regarding whether this action could help obtain funding for trails; what prompted this action; if ABAG has a vetting process; the eligibility criteria; how the PCA’s would benefit the RHNA numbers; if there are any disadvantages.
Chair Strauss opened the meeting to public comments.
Mr. Rene Voss, Alderney Avenue, made the following comments:
• He thanked staff for nominating these open space areas. • This will help with fundraising.
• He suggested they change the allocation type from “recreation” to “natural lands”.
Mr. Jonathon Braun, Co-Chair of the Open Space Committee, made the following comments:
558
4 • He supports adoption of the Resolution.
• He agreed with Mr. Vos about the allocation type.
• He noted a mistake in the resolution- the reference to Measure J should be changed to Measure A.
Chair Strauss closed the meeting to public comments.
Staff responded to the comments made by the public.
Commissioner Pipkin provided the following comment:
• This is a great opportunity to be able to leverage the open space areas.
Commissioner Asselstine provided the following comments:
• A lot of time has been spent looking at Sorich Park and the possibility of multi-modal trails.
• A description of ABAG’s objectives would be helpful.
Commissioner Smith provided the following comments:
• He uses both parks.
• He appreciates the opportunities that could come from either designation. • He supports trail improvements.
M/s, Tunny/Asselstine, motion to Adopt a Resolution Recommending the Town Council Nominate Sorich Ranch Park and Faude Park as Two Priority Conservation Areas and Authorize Submission to the Association of Bay Area Governments (ABAG).
Ayes: Asselstine, Heiman, Pipkin, Smith, Tunny, Chair Strauss
5. Public Hearings
D. Consideration of the Adoption of a Resolution Recommending Town Council Approval to Repeal and Replace Title 4, Public Welfare, Morals, and Conduct, Chapter 13, Private Trees, and Establishment of a Tree Preservation In-Lieu and Fee and recommending the proposed regulations are exempt from CEQA pursuant To CEQA Guidelines 15016(b)(3)
M/s, Asselstine/Tunny, to continue this item to the May 5th meeting.
Ayes: Asselstine, Heiman, Pipkin, Smith, Tunny, Chair Strauss
6. Business Items- None
7. Future Agenda Items and/or Commissioner Reports
Commissioner Pipkin discussed the recent tragedy involving six Archie Williams High School students.
8. Adjournment- Chair Strauss adjourned the meeting at 9:05 p.m. The next meeting is scheduled for Monday, May 5, 2025 at 7:00 p.m.
Respectfully submitted,
Toni DeFrancis
Recording Secretary
559