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Report regarding consideration of Design Review and Initial Study/Mitigated Negative Declaration to construct one new single-family residential building at 52 Franklin Avenue (Assessor’s Parcel Number 012039180) in the Low Density Residential (RL-8) Zoning District. (Billy Gross, Principal Planner)
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MOTIONS TO ADOPT STAFF RECOMMENDATIONS:
1. Move to adopt the resolution adopting the Initial Study/Mitigation Negative Declaration.
2. Move to adopt the resolution approving Design Review and other Planning entitlements subject to the attached draft Findings and draft Conditions of Approval.
RECOMMENDATION
Recommendation
Staff recommends that the Planning Commission conduct a public hearing and take the following actions:
1. Adopt a resolution making findings and adopting the Initial Study/ Mitigated Negative Declaration (ND25-0001) for the 52 Franklin Ave Residential Project in accordance with CEQA Guidelines Section 15070 et seq; and,
2. Adopt a resolution making findings and approving the Design Review and other Planning entitlements request for Project P22-0027 , including Design Review (DR22-0045), for the 52 Franklin Ave Residential Project within the Residential Low-Density (RL-8) Zoning District, subject to the draft Conditions of Approval.
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BACKGROUND/DISCUSSION
Site Overview
The project site is located at 52 Franklin Avenue, near the end of the cul-de-sac at the street terminus, with a total area of 8,422 square feet. The project site is vacant resulting from a mudslide in 1982 that moved the garage and a portion of the previous residence on the site into the street. Portions of the old foundation still appear on the site. The development area of the site is relatively flat, with a 10 percent slope along Franklin Avenue that rises to a 60 percent slope in the mid-and rear portions of the lot. The varying topography is predominately from cut and fill activities and slope instability. The site is adjacent to single-family residences to the east and west and backs up to privately owned open space to the south (Sign Hill).
Proposed Project
Subsequent geotechnical and geologic investigation on the site concluded that the potential for a future debris flow still exists due to susceptible soils on the steeper, upper portions of the property and the hillside above the rear property line. As an environmental mitigation measure to protect against such a debris flow, the project proposes to construct a “U” shaped debris barrier on the rear one-third of the site. The debris barrier would consist of retaining walls to form a basin that would capture and enclose a potential debris flow onto the Project site. An eight-foot-wide setback along the western property line would allow access to the debris capture area for equipment to remove debris captured within the basin, as needed.
A two-story single-family residence would be constructed in front of the debris barrier on the front two-thirds of the lot, with a total gross floor area of 2,528 square feet and an attached 788 square foot garage. Due to the slope of the lot, the general design of the residence will be like neighboring properties, with the ground floor consisting of a two-car garage directly off the street and crawl space behind, and all habitable space located on the second floor.
The design is traditional in nature, with large windows and balconies on the front elevation facing Franklin Avenue. The exterior cladding will be a combination of horizontal siding on the upper story and stucco on the lower story, with a hipped roof. Private open space is provided through a combination roof deck / rear deck at the rear of the house. The landscaping plan consists of a mixture of ground cover, shrubs and a tree in the front yard.
Entitlements Request
The Project is seeking the following entitlements, discussed in detail in this staff report:
• CEQA Determination
• Design Review
ZONING CONSISTENCY ANALYSIS
The subject site is located within the Residential Low-Density 8 (“RL-8”) Zoning District, which allows development at a density of eight units per acre. The proposed project would meet the basic development standards of the RL-8 district, as indicated in Table 1 below:
Table 1: RL-8 Development Standard Compliance
|
|
Requirement |
Proposal |
|
Minimum Lot Size |
5,000 SF |
8,422 SF |
|
Maximum Density |
2 units |
1 unit |
|
Maximum Height |
28’-0” |
27’-5” |
|
Maximum Number of Stories |
2 |
2 |
|
Minimum Setbacks |
|
|
|
Front |
15’ |
15’ |
|
Side |
5’ |
5’ |
|
Rear |
20’ |
> 20’ |
|
Maximum Floor Area Ratio (FAR) |
.50 |
.40 |
|
Maximum Lot Coverage |
50% |
30% |
Section 20.330.004 of the Zoning Code requires two parking spaces for the proposed project, at least one of which must be located within a garage. The project, as proposed, meets this parking requirement.
All residential projects are also regulated by Zoning Code Chapter 20.310 Site and Building Design Standards. This chapter includes regulations related to grading, drainage and hillside development (Section 20.310.002 General Site and Building Design) and regulations specific to low-density residential projects (Section 20.310.003 Single-Family and Duplex Residential Design). In general, these standards require that site grading is balanced, that hillside development is articulated and does not include building faces greater than 20 feet in height, and provides objective design standards. The project, as proposed, complies with all applicable regulations.
GENERAL PLAN CONSISTENCY ANALYSIS
The subject property has a General Plan land use designation of Low Density Residential. This designation is intended for residential development, with densities up to eight dwelling units per acre. The project, as proposed, is consistent with the General Plan guiding and implementing policies related to infill of underutilized sites and preserving the character and scale of residential neighborhoods.
DESIGN REVIEW BOARD
The Design Review Board (DRB) reviewed the project on July 15, 2025, and were supportive of the project, recommending approval with minor revisions to the debris barrier wall finish and landscape plan, and with a request to provide more documentation on the site drainage. A condition of approval is included, to ensure that the applicant incorporates the Board’s final comments and recommendations in the building permit submittal. The complete DRB meeting minutes are included in Attachment 1 to this staff report.
ENVIRONMENTAL REVIEW
Initial Study / Mitigated Negative Declaration
Typically, the construction of one single-family residence in a residential zone with utilities and infrastructure in place is categorically exempt from the California Environmental Quality Act (CEQA) requirements under CEQA Guidelines section 15303, Class 3 New Construction or Conversion of Small Structures. However, there are exceptions to exemptions as stated in CEQA Guidelines section 15300.2, subsection (a), which notes that a project that in itself “is ordinarily insignificant in its impact on the environment may in a particularly sensitive environment be significant.” Therefore, if a project may be located in a biological habitat, or on steep or potentially unstable slopes, the exception to the exemption noted above requires the lead agency to complete an Initial Study.
A Draft Initial Study/ Mitigated Negative Declaration (IS/MND) was prepared by RCH Group and Allison Knapp Consulting. The Draft IS/MND identifies the potential for significant environmental impacts related to Biological Resources and Geology & Soils, all of which can be mitigated to a less than significant impact with the incorporation of specific mitigation measures, as discussed below.
Biological Resources
Because there are several large trees on the steep slope of the southern portion of the project site that are planned for removal, there is the potential for raptors (birds of prey) and other protected birds to nest on and adjacent to the site. These birds are protected under the Migratory Bird Treaty Act and Fish and Game Code 3503.5. If construction begins during nesting season (February 15-August 31), potentially significant impacts could occur. The implementation of Mitigation Measure BIO-1 Pre-Construction Nesting Birds Survey would reduce this impact to a less-than-significant level.
BIO-1: Pre-Construction Nesting Birds Survey. If Project construction activities occur during the nesting season (approximately February 15 to August 31), for birds protected under the California Fish and Game Code and Federal (MBTA) the applicant shall retain a qualified biologist to conduct a preconstruction survey for protected birds on the site and in the immediate vicinity. The survey shall be done no more than 14 days prior to the initiation to construction activities. If nesting birds are found on the Project site or in the immediate vicinity, the developer shall locate and map the nest site(s) within three days and submit a report to the City and California Department of Fish and Wildlife ("CDFW"),
establish a no-disturbance buffer of 250-feet, and conduct on-going weekly surveys to ensure the no-disturbance buffer is maintained. In the event of destruction of a nest with eggs, or if a juvenile or adult raptor should become stranded from the nest, injured or killed, the qualified biologist shall immediately notify the CDFW. The qualified biologist shall coordinate with the CDFW to have the injured bird either transferred to a raptor recovery center or, in the case of mortality, transfer it to the CDFW within 48 hours of notification. These procedures reduce the potential for the disturbance of nesting birds or the destruction of active nests. Implementation of this mitigation would reduce the potential impacts from
significant to mitigable.
Tree removal outside of the nesting season would preclude the need for any other mitigation activities related to protected birds.
There is also the potential for hoary bats to roost within the large trees. Roosting bats are protected under the Fish and Game Code. Disturbance of any roosting bats would be a significant environmental impact. To protect any roosting bats, the implementation of Mitigation Measure BIO-2 Pre-Construction Roosting Bat Survey would reduce this impact to a less-than-significant level.
BIO-2: Pre-Construction Roosting Bat Survey. Removal or pruning of trees could result in the destruction of bat roosts or disruption of breeding of special-status bats such as the hoary bat. In addition, disturbance during the maternity roosting season could result in potential roost abandonment and mortality of young. Prior to the removal or pruning of any trees or the commencement of construction activities within 100 ft of mature trees, the following avoidance measures should be performed.
1. Bat Habitat Assessment. If work is to take place during the bat breeding season (April 1 through August 31), a qualified biologist should conduct a survey of the project site and vicinity to determine if active maternity roosts are present. This survey should be conducted no more than 14 days prior to the initiation of work.
2. Maternal Roosts. If any trees or structures are determined to support or potentially support maternal bat roosts, work may not proceed if it would destroy or disrupt breeding. Maternal bat roost sites may only be removed or demolished after coordination with the CDFW and/or the USFWS. Passive exclusion of roosting bats would be required and this may only be performed during the non-breeding season (i.e., between October 1 and March 30).
3. Pre-construction Survey. A pre-construction survey should be conducted by a qualified biologist to identify suitable bat roosting sites. The study area should include an area extending up to 100 ft of the limits of work, access permitting.
4. Protocol for Observations of Live Bats. If live bats are detected in the work area, work may not proceed until CDFW has been consulted. Contractor or others may not attempt to disturb (e.g., shake, prod) roosting features to coax bats to leave. Such actions would constitute “harassment” under the CCR.
5. Day or Night Roosts. Any trees or structures present on site and determined to provide suitable day or night roosting sites for bats should be identified and marked on site plans. If no suitable roost sites or evidence of bat roosting are identified, impact minimization measures are not warranted. If suitable roosting sites or evidence of bat roosting are identified, the following measures should be conducted in coordination with CDFW:
a. A qualified biologist should survey suitable roost sites immediately prior to the removal or significant pruning of any of the larger trees, or demolition or significant renovation of any structures suspected or known to support bat roosts.
b. If the project biologist identifies suitable day or night roost sites or evidence of bat occupation, the following steps should be followed to discourage use of the sites by bats and to ensure that any bats present are able to safely relocate.
For trees:
a. Tree limbs smaller than three inches in diameter should be removed and any loose bark should be peeled away.
b. Any competing limbs that provide shelter around the potential roost site should be removed to create as open of an area as possible.
c. The tree should then be alone to allow any bats using the tree/snag to find another roost during their nocturnal activity period.
d. Trees should be re-surveyed 48 hours after trimming.
e. If no bats are present, work may proceed.
f. If bats remain on site, additional measures would be prescribed by the biologist.
Geology and Soils
Geotechnical mitigation measures on the site included as Project design would consist of constructing a “U” shaped debris barrier, consisting of retaining walls, to form a basic that would capture and enclose a potential debris flow onto the Project site. The debris flow capture capacity is estimated at 543 cubic yards, which exceeds the recommendation of 500 cubic yards by the applicant’s geotechnical consultants (confirmed by the City’s geotechnical consultant peer review). An eight-foot-wide setback along the western property line would allow access to the debris capture area for equipment to remove debris within the basin, as needed. An unmaintained debris basin would not adequately prevent damage to the proposed residence during a future debris flow or landslide event, which would be a potentially significant environmental impact. The implementation of Mitigation Measure GEO-1 Debris Basin Maintenance Plan would reduce impacts to a less than significant level.
GEO-1: Debris Basin Maintenance Plan. A Maintenance Program for the Debris Basin (“Basin”) shall be prepared, and peer reviewed by the City’s Engineering and Building Divisions and/or their designee. The Maintenance Program shall be modified as directed by the City. At a minimum, the Maintenance Program shall define the type of inspections, frequency (taking into account periods of intense or prolonged rainfall), and maintenance of the Basin and support structures. Inspections and recommendations shall be conducted and developed by a California state licensed engineering geologist or geotechnical engineer. Inspection reports shall be provided to the City of SSF Building and/or Engineering Division. City permits (i.e., Building, Engineering, Planning) shall be obtained prior to commencement of construction and all permits shall require a final inspection. This requirement shall be recorded on the title to the property. Said recordation is required prior to issuance of any building or grading permits for the property known as 52 Franklin Avenue, South San Francisco, CA
Public Comments
The Draft IS/MND was submitted to the State Clearinghouse and was circulated on October 15, 2025 for a 30-day public and agency review period. The City did not receive any comment letters from the public or reviewing agencies during the 30-day period.
CONCLUSION
The proposed single-family development is consistent with both General Plan goals and the Zoning Ordinance requirements. The project is an infill residential project on a site that is zoned for residential development. The CEQA analysis determined that the potential for significant environmental impacts related to Biological Resources and Geology & Soils can be mitigated to a less than significant impact with the incorporation of specific mitigation measures.
Therefore, staff recommends that the Planning Commission take the following actions:
1. Adopt a resolution making findings and adopting the Initial Study/ Mitigated Negative Declaration (ND25-0001) for the 52 Franklin Ave Residential Project in accordance with CEQA Guidelines Section 15070 et seq; and,
2. Adopt a resolution making findings and approving the entitlements request for Project P22-0027, including Design Review (DR22-0045), for the 52 Franklin Ave Residential Project within the Residential Low-Density (RL-8) Zoning District, subject to the draft Conditions of Approval.
Attachments
1. Design Review Board Meeting Minutes of July 15, 2025
Associated Documents and Exhibits
1. 52 Franklin CEQA Resolution (File ID#25-1173)
A. Initial Study and Mitigated Negative Declaration
2. 52 Franklin Entitlements Resolution (File ID#25-1174)
A. Conditions of Approval
B. 52 Franklin Project Plan Set
C. 52 Franklin Debris Barrier Plan Set