Subject Area: Walls
INTRODUCTION
This recommended revision supports the purpose and intent of walls as they relate to neighborhood compatibility. Fences and walls detached from a retaining wall can function as a required safety guardrail. However, these are not subject to the same development standards as traditional guardrails constructed on top of retaining walls. A guardrail on top of a retaining wall shall not exceed the minimum required height, and must be transparent in nature. The current code may be interpreted to allow solid structures to be located very close to the top of a retaining wall, resulting in massing that appears as a solid face. Although the individual structures may not exceed the height limits, the combined height and mass may appear inconsistent with the City’s design guidelines and may have a negative impact on the visual scene and community character. This zoning amendment would address several concerns:
Add section references to applicable code sections for wall exceptions; A minimum setback between a retaining wall and a fence or wall; Any structure serving the purpose of a guardrail for a retaining wall will be subject to the same design standards as guardrails;
Landscaping shall be planted in front of retaining walls to further break up the massing of these structures within front-yard setbacks, street-side yard setbacks, rear-yard setbacks for through lots, Inland Canyon (IC) or Coastal Canyon Overlay Zoning Districts, and 10 feet from Open Space Zones or open space easements. “REDLINE” VERSION OF PROPOSED CHANGE
Section 17.24.180 is amended as follows:
17.24.180 Retaining Walls.
A. Purpose and Intent. In a community with sloping topography, retaining walls are often necessary to create developable or usable areas. The purpose and intent of this section is to establish standards that allow for retaining walls, while limiting their visual and traffic impacts. The purpose of a stricter height limit in the front yard is to provide for an open street scene, to allow the primary structures on a street to be visible and to contribute to the visual character of the neighborhood, and to allow for unobstructed views of traffic to and from driveways. The standards are also meant to minimize the height of retaining walls and their impacts upon adjacent structures.
B. Standards for Retaining Walls In All Zones.
1. Construction and Maintenance. Retaining walls shall be constructed and maintained so that they do not constitute a hazard to traffic, persons or property.
2. Measuring Height. The height of retaining walls shall be measured from the lower side of finished grade to the top of the retaining wall.
Attachment 5
3. Landscaping. There shall be a minimum of a two-foot-deep area at the base of retaining walls in the following areas that shall be planted consistent with landscape standards in Section 17.68.040:
a. Front Yard Setbacks.
b. Street-Side Yard Setbacks.
c. Within Inland Canyon (IC) Overlays or Coastal Canyon Setbacks. d. Within 10 feet from Open Space zones or open-space easements.
C. Standards for Retaining Walls in Nonresidential Zones. The height limit, design, materials, stepping, and other retaining wall features of retaining walls are reviewed and approved through an architectural review process with the required approval of a Development Permit (Section 17.16.100), or a Cultural Heritage Permit (Section
17.16.110) for historic resources and landmarks on the City's designated historic resources and landmarks list.
D. Standards for Retaining Walls in Residential Zones. Unless otherwise provided for in the applicable zones, the following standards shall apply to retaining walls and to all structural elements supporting the retaining walls, including pilasters, trellises, etc. In addition to the regulations set forth in this section, all retaining walls shall be constructed and maintained so that they do not constitute a hazard to traffic, persons, or property.
1. Height Limits. The maximum height limits for residential retaining walls are shown in Table 17.24.180, Height Limits for Residential Retaining Walls, below.
Table 17.24.180
Height Limits for Residential Retaining Walls
Area of Lot Maximum Height Limit
Front Yard
Setback
Area
3 ft. 6 in.
Interior Side
Yard
Setback
Area
6 ft., except when the retaining wall faces toward the subject property, in which case the retaining wall shall not exceed 8 ft. 6 in. in height.
Street-Side
Yard
Setback
Area
Reverse corner lot 3 ft. 6 in. Corner lot: Within 5 ft. of street-side property line: 3 ft. 6 in. Remaining width of the street side yard: 6 ft.
Rear Yard
Setback
Area
6 ft., except when the retaining wall faces toward the subject property, in which case the retaining wall shall not exceed 8 ft. 6 in. in height.
Other Areas
of Lot
6 ft., except when the retaining wall faces toward the subject property, in which case the retaining wall shall not exceed 8 ft. 6 in. in height.
2. Stepping of Retaining Walls. A number of retaining walls (stepping) may be constructed to substitute for one tall retaining wall if both of the following occur:
a. The height of each retaining wall must comply with the height limits of Table 17.24.180, Height Limits for Retaining Walls, above; and b. The minimum distance between any two retaining walls shall be equal to or greater than the height of the taller of the two retaining walls. The distance between the two walls shall be measured as the horizontal separation between the two closest wall faces: the back face of the downslope retaining wall and the front face of the up slope retaining wall.
The distance between stepped walls in-the-bank-garages may be reduced with the approval a minor exception permit as described in Section
17.16.090, Minor Exception Permits.
3. Distance Between Retaining Walls and Other Walls, Fences, or Similar Structures. The minimum distance between a retaining wall and any other wall, fence, or similar structure shall be equal to or greater than the height of the taller of the two structures, measured from the back face of the retaining wall and the front face of the adjacent structure.
Figure 17.24.180
43. Guardrail Requirements.
a. Guardrail Height. The height of guardrails constructed on top of retaining walls 30 inches or more in height shall be no higher than the minimum height required by comply with the Building Code. The height is measured from the top of the retaining wall to the top of the guardrail. When swimming pools are proposed, the height of the guardrails shall be no higher than the minimum height required by the Swimming Pool Code. b. Materials for Guardrails. Guardrails shall be designed and constructed of materials that limit visual impacts. Unless the City Planner finds it is unnecessary to limit visual impacts, any structure serving as a required guardrails and shall be designed or constructed of materials that are mostly open or transparent when retaining walls are located in a front yard setback, rear yard setback (on through lots), street side yard setback (within five feet of street side property line), or in other instances where retaining walls are in a location or have a height that will have significant visual impacts, shall be designed or constructed of materials that are mostly open or transparent. unless guardrails are mostly open. Guardrails are "mostly open" when they are constructed of materials that may include, but are not limited to glass or have metal or wood pickets. The City Planner determines if the design and materials of guardrails will adequately limit visual impacts. The City Planner's decision may be appealed per Chapter 17.12.140.
c. Guardrails with Pilasters. When incorporated into guardrails required by the Building Code, pilasters shall be allowed above retaining walls as follows:
i. The maximum height of pilasters shall not exceed 42 inches as measured from the top of the retaining wall to the top of pilasters. In the case where swimming pools are proposed, the height of the pilasters shall be no higher than the minimum height required by the Swimming Pool Code.
ii. The minimum centerline distance between pilasters shall not be less than six feet when the pilaster is part of the required guardrail and not less than four feet when the pilaster is part of the required hand rail for stairways.
54. Exceptions.
a. The following exceptions are allowed with the approval of a Minor Exception Permit per Section 17.16.090, of this title.
i. An increase in the permitted height of retaining walls up to a maximum height of six feet for walls located in front yards, rear yards (on through lots), or located within five feet of street-side yard property lines.
ii. An increase in the permitted height of a retaining wall up to a maximum height of eight feet, six inches for walls not located in front yards, rear yards (on through lots), or street-side yards. b. Required Findings. In addition to the general findings required for specific permit in Section 17.16.090(F)s, all of the following findings shall be made prior to the approval of a Minor Exception Permit to exceed the standards for retaining walls:
i. The height of the retaining wall will not be unsightly or incompatible with the character of or uses in the neighborhood;
ii. The height of the retaining wall will not have negative visual impacts upon the street scene or obstruct views of traffic to and from driveway;
iii. The additional height is necessary, given topographical constraints.