Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Tom Sullivan
530 Barron Ave
Palo Alto, CA 94306
Site: 530 Barron Ave., Palo Alto
Dear Tom,
At your request I visited the above site for the purpose of inspecting and commenting on the regulated trees around the property. A new home is planned and a porti on of the existing home will be converted into an ADU, prompting the need for this tree protection report.
Method:
Palo Alto regulates the following trees:
Locally Native Protected Species Trees
Big Leaf Maple (Acer macrophyllum) 11.5" or more DBH
California Incense Cedar (Calocedrus decurrens) 11.5" or more DBH Coast Live Oak (Quercus agrifolia) 11.5" or more DBH
Blue Oak (Quercus douglasii) 11.5" or more DBH
California Black Oak (Quercus kelloggii) 11.5" or more DBH Valley Oak (Quercus lobata) 11.5" or more DBH
Coast Redwood (Sequoia sempervirens) 18" or more DBH
Protected Mature Trees
Any mature tree measuring 15" or more DBH
Invasive species trees and high water use trees are excluded.
Designated Trees
Any tree designated for protection during review and approval of a development project.
Public Trees / Street Trees
"Public trees" include any tree, in any street, park, or public place in the city of Palo Alto. "Street Tree" refers to the Public Trees located in the city road right of way.
Palo Alto requests that all trees with a trunk diameter greater than 6 inches at standard height be included in the report including all street trees and trees on neighboring properties that might be impacted.
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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The location of the regulated trees on this site can be found on the plan provided by you. Each tree is given an identification number. The trees are measured at 54 inches above ground level (DBH or Diameter at Breast Height). A condition rating of 1 to 100 is assigned to each tree representing form and vitality on the following scale:
1 to 29 Very Poor
30 to 49 Poor
50 to 69 Fair
70 to 89 Good
90 to 100 Excellent
The height and spread of each tree is estimated. A Comments section is provided for any significant observations affecting the condition rating of the tree.
A Summary and Tree Protection Plan are at the end of the survey providing recommendations for maintaining the health and condition of the trees during and after construction.
Photos of the trees can be found in the Appendix at the end of the report.
Appraised values and their calculations can be found in the Appendix at the end of the report.
Alternative design approaches can be found in the Appendix at the of this report.
If you have any questions, please don’t hesitate to call.
Sincerely
Robert Weatherill
Certified Arborist WE 1936A
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Tree Survey
Tree# Species DBH Ht/Sp Con Rating Comments
1 Coastal redwood 107.2”@2’ 90/40 65 Good health, fair condition, Sequoia sempervirens codominant at 2’, Regulated
2 Coastal redwood 51.0” 90/20 70 Good health and condition Sequoia sempervirens Regulated
3 Coastal redwood 36”est 80/30 65 Good health and condition, neighbor’s Sequoia sempervirens t r e e , Regulated
Summary:
Tree # 1 is a coastal redwood in the middle of the property. The tree is a Locally Native Protected Species. The tree is co-dominant at approximately 4 feet above grade. The tree splits into 5 large trunks. The size and location of this tree prohibits any type of development on this property and the tree has been requested for removal.
Tree # 2 is a coastal redwood at the side of the property. The tree is a Locally Native Protected Species. The tree is in good health and condition and should be protected during construction.
Tree # 3 is a coastal redwood on the rear neighbor’s property. The tree is a Locally Native Protected Species. The tree is in good health and condition and should be protected during construction.
Tree Protection Plan
1. The Tree Protection Zone (TPZ) should be defined with protective fencing. This should be cyclone or chain link fencing on 11/2” or 2” posts driven at least 2 feet in to the ground standing at least 6 feet tall. Normally a TPZ is defined by the dripline of the tree. I recommend the TPZ’s as follows:-
Tree # 2: TPZ should be at 42 feet from the trunk of the tree, closing on the property line. This is shown as a thin red line.
The TPZ can be reduced to accommodate the new construction allowing for safe access to the construction.
Any work within the TPZ should be done with hand tools only.
Any roots greater than 2” in diameter should be worked around rather than cut.
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Tree # 3: TPZ should be at 30 feet from the trunk of the tree, closing on the property line. This is shown as a thin red line.
The TPZ can be reduced to accommodate the new construction allowing for safe access to the construction.
Any work within the TPZ should be done with hand tools only.
Any roots greater than 2” in diameter should be worked around rather than cut.
2. Any pruning and maintenance of the trees shall be carried out before construction begins. This should allow for any clearance requirements for both the new structure and any construction machinery. This will eliminat e the possibility of damage during construction. The pruning should be carried out by an arborist, not by construction personnel. No limbs greater than 4” in diameter shall be removed.
3. Any excavation in ground where there is a potential to damage roots of 1” or more in diameter should be carefully hand dug. Where possible, roots should be dug around rather than cut.(2)
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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4. If roots are broken, every effort should be made to remove the damaged area and cut it back to its closest lateral root. A clean cut should be made with a saw or pruners. This will prevent any infection from damaged roots spreading throughout the root system and into the tree.(2)
5. Do Not:.(4)
a. Allow run off or spillage of damaging materials into the area below any tree canopy. b. Store materials, stockpile soil, park or dr ive vehicles within the TPZ of the tree. c. Cut, break, skin or bruise roots, branches or trunk without first obtaining permission from the city arborist.
d. Allow fires under any adjacent trees.
e. Discharge exhaust into foliage.
f. Secure cable, chain or r ope to trees or shrubs.
g. Apply soil sterilants under pa vement near existing trees.
6. Where roots are exposed, they should be kept covered with the native soil or four layers of wetted, untreated burlap. Roots will dry out and die if left exposed to the air for too long.(4)
7. Route pipes into alternate locations to avoid conflict with roots.(4)
8. Where it is not possible to reroute pipes or trenches, the contractor is to bore beneath the dripline of the tree. The boring shall take place no less than 3 feet below the surface of the soil in order to avoid encountering “feeder” roots.(4)
9. Compaction of the soil within the dripline shall be kept to a minimum. (2) If access is required to go
through the TPZ of a protected tree, the area within the TPZ should be protected from compaction either with steel plates or with 4” of wood chip overlaid with plywood.
10. Any damage due to construction activities shall be reported to the project arborist or city arborist within 6 hours so that remedial action can be taken.
11. Ensure upon completion of the project that the original ground level is restored
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Location of proposed home, ADU, tree requested for removal, protected trees and their Tree Protection Zones
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Glossary
Canopy The part of the crown composed of leaves and small twigs.(2) Cavities An open wound, characterized by the presence of extensive decay and resulting in a hollow.(1)
Decay Process of degradation of woody tissues by fungi and bacteria through the decomposition of cellulose and lignin(1)
Dripline The width of the crown as measured by the lateral extent of the foliage.(1) Genus A classification of plants showing similar characteristics.
Root plate The point at which the trunk flares out at the base of the tree to become the root system.
Species A Classification that identifies a particular plant.
Standard Height at which the girth of the tree is measured. Typically 4 1/2 feet above height ground level
References
(1) Matheny, N.P., and Clark, J.P. Evaluation of Hazard Trees in Urban Areas.
International Society of Arboriculture,1994.
(2) Harris, R.W., Matheny, N.P. and Clark, J.R.. Arboriculture: Integrated Management of Landscape Trees, Shrubs and Vines. Prentice Hall, 1999. (3) Carlson, Russell E. Paulownia on The Green: An Assessment of Tree Health and Structural Condition. Tree Tech Consulting, 1998.
(4) Extracted from a copy of Tree Protection guide lines. Anon (5) T. D. Sydnor, Arboricultural Glossary. School of Natural Resources, 2000 (6) D Dockter, Tree Technical Manual. City of Palo Alto, June, 2001
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Certification of Performance(3)
I, Robert Weatherill certify:
* That I have personally inspected the tree(s) and/or the property referred to in this report, and have stated my findings accurately. The extent of the evaluation and appraisal is stated in the attached report and the Terms and Conditions;
* That I have no current or prospective interest in the vegetation or the property that is the subject of this report, and I have no personal interest or bias with respect to the parties involved;
* That the analysis, opinions and conclusions stated herein are my own, and are based on current scientific procedures and facts;
* That my compensation is not contingent upon the reporting of a predetermined conclusion that favors the cause of the client or any other party, nor upon the results of the assessment, the attainment of stipulated results, or the occurrence of any subsequent events;
* That my analysis, opinions, and conclusions were developed and this report has been prepared according to commonly accepted Arboricultural practices;
* That no one provided significant professional assistance to the consultant, except as indicated within the report.
I further certify that I am a member of the International Society of Arboriculture and a Certified Arborist. I have been involved in the practice of arboriculture and the care and study of trees for over 20 years.
Signed
Robert Weatherill
Certified Arborist WE 1936a
Date: 6/23/25
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Terms and Conditions(3)
The following terms and conditions apply to all oral and written reports and correspondence pertaining to consultations, inspections and activities of Advanced Tree Care :
1. All property lines and ownership of property, trees, and landscape plants and fixtures are assumed to be accurate and reliable as presented and described to the consultant, either verbally or in writing. The consultant assumes no responsibility for verification of ownership or locations of property lines, or for results of any actions or recommendations based on inaccurate information.
2. It is assumed that any property referred to in any report or in conjunction with any services performed by Advanced Tree Care, is not in violation of any applicable codes, ordinances, statutes, or other governmental regulations, and that any titles and ownership to any property are assumed to be good and marketable. Any existing liens and encumbrances have been disregarded.
3. All reports and other correspondence are confidential, and are the property of Advanced Tree Care and it’s named clients and their assignees or agents. Possession of this report or a copy thereof does not imply any right of publication or use for any purpose, without the express permission of the consultant and the client to whom the report was issued. Loss, removal or alteration of any part of a report invalidates the entire appraisal/evaluation.
4. The scope of any report or other correspondence is limited to the trees and conditions specifically mentioned in those reports and correspondence. Advanced Tree Care and the consultant assume no liability for the failure of trees or parts of trees, either inspected or otherwise. The consultant assumes no responsibility to report on the condition of any tree or landscape feature not specifically requested by the named client.
5. All inspections are limited to visual examination of accessible parts, without dissection, excavation, probing, boring or other invasive procedures, unless otherwise noted in the report. No warrantee or guarantee is made, expressed or implied, that problems or deficiencies of the plants or the property will not occur in the future, from any cause. The consultant shall not be responsible for damages caused by any tree defects, and assumes no responsibility for the correction of defects or tree related problems.
6. The consultant shall not be required to provide further documentation, give testimony, be deposed, or attend court by reason of this appraisal/report unless subsequent contractual arrangements are made, including payment of additional fees for such services as described by the consultant or in the fee schedules or contract.
7. Advanced Tree Care has no warrantee, either expressed or implied, as to the suitability of the information contained in the reports for any purpose. It remains the responsibility of the client to determine applicability to his/her particular case.
8. Any report and the values, observations, and recommendations expressed therein represent the professional opinion of the consultants, and the fee for services is in no manner contingent upon the reporting of a specified value nor upon any particular finding to be reported.
9. Any photographs, diagrams, graphs, sketches, or other graphic material included in any report, being intended solely as visual aids, are not necessarily to scale and should not be construed as engineering reports or surveys, unless otherwise noted in the report. Any reproductions of graphs material or the work product of any other persons is intended solely for the purpose of clarification and ease of reference.
Inclusion of said information does not constitute a representation by Advanced Tree Care or the consultant as to the sufficiency or accuracy of that information.
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Appendix
Photos of trees
Tree # 1
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Tree # 2
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Tree # 3
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Addendum
Appraised Value of Tree # 1 using Trunk Formula Method
Tree# Species DBH Ht/Sp Con Rating Comments
1 Coastal redwood 107.2”@2’ 90/40 65 Good health, fair condition, Sequoia sempervirens 32.2”, 30.5”, 28.1”, 41.3”, 46.2” at 6 feet above grade Codominant at 2’, Regulated
Tree # 1 is a large redwood with a trunk diameter of 107.2” at 2 feet above grade. The tree starts to develop co-dominant stems at 3 feet and has ultimately 5 co-dominant stems at around 6 feet above grade. Appraising the value of the tree using the diameter at 2 feet above grade does not give a fair and realistic value of the tree, because the appraisal assumes that the trunk is a single trunk of 107” which it most definitely is not. I have remeasured the tree at 6 feet above grade and used these values to determine the appraised value of the tree.
Diameter of trunks at 6 feet above grade: 32.2”, 30.5”, 28.1”, 41.3”, 46.2”.
To determine the cross-sectional area of the entire tree I have added the cross-sectional areas of each trunk.
Cross Sectional Area of entire tree = 814 + 730 + 620 + 1339 + 1676 = 5179 square inches
The resulting value of the tree is $94,300.00. See attached table of calculations.
Appraised Value of Tree # 1 using Cost of Reproduction, Cost Compounding Technique
Tree# Species DBH Ht/Sp Con Rating Comments
1 Coastal redwood 107.2”@2’ 90/40 65 Good health, fair condition, Sequoia sempervirens 32.2”, 30.5”, 28.1”, 41.3”, 46.2” at 6 feet above grade Codominant at 2’, Regulated
Using the same figures adopted in the Trunk Formula Method for Health, Structure, Form, Functional and External Conditions.
Years to parity in this location with ideal irrigation and growing conditions would be approximately 75 years.
Interest rate as of today current mortgage rate, 30yr fixed, 6.87%
Removal of existing tree and clean up cost $15,000.00
The resulting value of the tree is $41,300.00. See attached table of calculations.
Advanced Tree Care 530 Barron Ave., Palo Alto
965 East San Carlos Ave, San Carlos June 23, 2025
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Alternative design approach around Tree # 1
I took a look at the plans dated 6/17/25 and it would certainly be possible to build the house as shown in the attached drawings. I do not think the tree would be adversely impacted as long as the foundations were designed to bridge over larger roots and compaction within the TPZ was kept to a minimum.
Redwoods are quite tolerant to construction impacts and can easily live through heavy canopy pruning without any problems. However, reducing this canopy to meet insurance requirements and balancing the canopy throughout would require removal of over 50% of the entire canopy and would leave an un sightly and poorly proportioned redwood.
A very recent consideration is house insurance. Many Cities are struggling to deal with protected trees that need to be removed due to cancellation of home insurance because the canopies of trees are growing over a home. I am encouraging homeowners and architects to not try to build a home beneath the canopy of the tree, because I do not think the issues with insurance in California are going away soon. This can be very challenging as housing density increases.
Redwoods have a high-water requirement to keep healthy. The proposed landscape may not be able to fulfill the requirements of this tree, and the tree may start to decline unless you provide annual supplemental irrigation. Redwoods are certainly not suited to this local climate as has been demonstrated by the decline of El Palo Alto.
Redwood roots will follow paths of moisture and a tree that is healthy like this, may impact the foundations of your new home if the roots find themselves in a water course beneath the new home.
The plans show the proposed home being 10 feet from the base of the tree and regardless of foundation design, I think building a new home this close to a large redwood is inviting structural problems several years down the line.
Line 9 Line 10 Line 11
Tree Tag #
Name (Initials)
WCISA Speces
Group
Classification
Booklet Page
Health
(Weighted
0.15)
Structure
(Weighted
0.70)
Form
(Weighted
0.15)
Overall
Condition
Rating (OCR)
"Weighted
Method"
Diameter
Inches at
2.0 ft. Above
Grade
Functional
Limitations
External
Limitations
WCISA
Species Group
Number
Trunk Square
Inches for
Replacement-
Size Specimen
of This
Average SF
Bay Area Cost
of 24 Inch Box
Tree (2019)
(UTC) Unit
Tree Cost per
Sq Inch (M
Divided by L)
Trunk Area
(TA) ((dia. x
dia.) x 0.785)
Basic
Functional
Replacement
Cost (BFRC) =
(OxN)
Depreciated
Functional
Replacement
Cost (DFRC) =
PxGxIxJ
Rounded-off
Appraised
Values
1 Ss 34 0.8 0.6 0.5 62% Multi 75% 75% 4 4.75 $250.00 $52.63 5179.00 272,578.95 $ 94,295 $ $94,300 $94,300
Valuation Appraisal Worksheet Based on Guide for Plant Appraisal, 10th Edition, 2nd Printing (2019) "Functional Replacement Method / Trunk Formula Technique" Address: 530 Barron Ave, Palo Alto
Date: 3/13/25
Depreciation Factors
Advanced Tree Care and Consultin g Inc.
965 East San Carlos Ave, San Carlos, CA 94070 650 839 9539 1 of 1
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Client name _____________________________________________________ Date _________ Case # ____________ Phone _________________________________________________________E-mail ______________________________ Address ___________________________________________________________________________________________ 4VCKFDUUSFF
Species ________________________________________________ _________________ 1. T runk diameter* (D) ______________ @ _________ %2. Condition rating
Health _______________________________________________________ Structure______________________________________________________ Form ________________________________________________________ ____________________________________________ _________ %3. Functional limitations ______________________________________________ _________ %4. External limitations 3FQMBDFNFOUUSFF
Species ________________________________________________ _________________ 5. T runk diameter* (D) ______________ @ ____________________) $__________6. Replacement tree and installation cost (Source:
_____________ $__________7. Site preparation (if any) and present value of aftercare (if any) __________8. T otal replacement tree cost $
$BMDVMBUJPOT
_________ yrs
_________ %
__________$
__________$
__________$
__________$
__________
Years to parity (appraiser’s judgment)**
Interest rate Source: ____________________________________________ Basic compounded cost (line 8 × [1+ line 10]line 9 ) Depreciated compounded cosUA (line 11 × line 2 × line 3 × line 4) Additional cleanup cost
T otal (line 12 + line 13)
Rounded $
* Diameter and cross-sectional area may be replaced with plant area, volume, or height as appropriate. ** The age and cross-sectional area of the subject tree are not necessarily relevant. Its size (diameter, volume, and/or height) is relevant.
Years to parity should reflect the appraiser’s best estimate at the time for a healthy specimen to reach a size where it provides equal utility or benefits.
A Apply depreciation if it is appropriate for the assignment.
Council of Tree & Landscape Appraisers (CTLA). 2019. Guide for Plant Appraisal, 10th Edition. International Society of Arboriculture, Atlanta, GA. 3FWJTFEJO$VSSFOUBTPG0DUPCFS
Tom Sullivan 6/19/25
408 223 5896 [email protected]
530 Barron Ave, Palo Alto
Coastal redwood, Sequoia sempervirens
107" 2'
62 80
60 50
75 75
Coastal redwood, Sequoia sempervirens
2.46" 54"
750.00Industry Standard
0 $750.00
75 6.87Current mortgage rate 30yr fixed
109,457.86
26,269.88
15,000
41,269
41,300