City of South San Francisco, CA Chapter 20.070 RESIDENTIAL ZONING DISTRICTS

§ 20.070.001 Purpose and Applicability.

The purpose of the residential zoning districts is to:

A. Accommodate a range of housing types consistent with the City's General Plan;

B. Preserve, protect, and enhance the character of the City's different residential neighborhoods and enhance the quality of life for the City's residents;

C. Ensure adequate light, air, privacy, and open space for each dwelling;

D. Ensure that all future development and alterations to existing structures are compatible with surrounding homes and appropriate to the physical characteristics of the site and the area where the project is proposed; and

E. Provide sites for public and semi-public land uses such as parks, libraries, and religious assembly uses to serve residents and complement surrounding residential development.

(Ord. 1646 § 2, 2022; Ord. 1656, 6/12/2024)

§ 20.070.002 Use Regulations.

Table 20.070.002: Use Regulations – Residential Zoning Districts, lists the uses permitted in the residential zoning districts and the level of review required. In cases where a specific land use or activity is not defined, the Chief Planner shall assign the land use or activity to a classification that is substantially similar in character. Use classifications and subclassifications that are not included in this table or not found to be substantially similar to the uses below are otherwise prohibited. The table also notes all regulations that apply to various uses.

Table 20.070.002: Use Regulations – Residential Zoning Districts
Use Classification	RL-2.2	RL-8	RM-22	RH-37.5 and RH-50	RH-180	Additional Regulations
“P” = Permitted; “M” = Minor Use Permit; “C” = Conditional Use Permit; “―” = Use Not Allowed
Residential Uses
Dwelling, Single-Unit
Detached	P	P	P	P	P	See Chapter 20.300, Airport Land Use Compatibility Plan Consistency
Semi-Attached	P	P	P	P	P
Attached	P	P	P	P	P
SB 9 Unit	P	P	―	―	―	See Chapter 20.300, Airport Land Use Compatibility Plan Consistency
Dwelling, Multiple-Unit
Duplex	―	―	P	―	―	See Chapter 20.300, Airport Land Use Compatibility Plan Consistency
Multifamily	―	―	P	P	P
Senior Citizen Residential	C	C	C	P	P
Group Residential	―	―	P	P	P	See Chapter 20.350, Group Residential
Live-Work	―	―	―	―	P	See Chapter 20.350, Live-Work Units
Mobile Home Park	―	―	C	C	―	See Chapter 20.350, Mobile Home Parks
Residential Care Facility
General	―	―	C	C	C	Subject to State licensing requirements
Limited	P	P	P	P	P	Subject to State licensing requirements
Senior	―	―	C	M	M	Subject to State licensing requirements
Supportive Housing
Domestic Violence Shelter	―	―	P1	P1	P1	See Chapter 20.350, Domestic Violence Shelter
Low Barrier Navigation Center	―	―	P	P	P	Subject to CA Government Code Sections 65660―65668
Permanent Supportive Housing	―	―	P	P	P	Subject to CA Government Code Sections 65650―65656
Public and Semi-Public Uses
College and Trade School, Public or Private	―	―	C2	C2	C2
Community Assembly
Small	―	M	M	M	P	See Chapter 20.300, Airport Land Use Compatibility Plan Consistency and Chapter 20.350, Community Assembly, Small and Large
Large	―	C	C	C	C
Community Garden	P	P	P	P	P
Cultural Institution	―	C	C	C	C
Day Care Center	―	P	P	P	P	See Chapter 20.300, Airport Land Use Compatibility Plan Consistency and Chapter 20.350, Day Care Centers
Elderly and Long-Term Care	―	C	C	C	C	See Chapter 20.300, Airport Land Use Compatibility Plan Consistency
Government Offices	―	―	―	C	C
Park and Recreation Facilities, Public	P	P	P	P	P
Public Safety Facilities	C	C	C	C	C
Schools, Public or Private	―	C	C	C	C	See Chapter 20.300, Airport Land Use Compatibility Plan Consistency
Social Service Facilities	―	―	―	M	M	See Chapter 20.350, Social Service Facilities
Commercial Uses
Crop Production, Limited	M	M	M	M	M
Lodging
Bed and Breakfast	M	M	M	M	M	See Chapter 20.300, Airport Land Use Compatibility Plan Consistency and Chapter 20.350, Bed and Breakfast Lodging
Short-Term Vacation Rental	P	P	P	P	P	See Chapter 20.350, Short-Term Vacation Rentals
Offices
Business and Professional	―	―	―	C3	C3
Medical and Dental	―	―	―	C3	C3
Walk-In Clientele	―	―	―	C3	C3
Personal Services
General Personal Services	―	―	―	C3	C3	See Chapter 20.350, Personal Services
Instructional Services	―	―	―	C3	C3
Transportation, Communication, and Utilities Uses
Communication Facilities
Antenna and Transmission Towers	See Chapter 20.370, Antennas and Wireless Communications Facilities and Chapter 20.375, Small Cell Wireless Communications Facilities
Utilities, Major	C	C	C	C	C	See Chapter 20.300, Airport Land Use Compatibility Plan Consistency
Utilities, Minor	P	P	P	P	P
Accessory Uses - See Chapter 20.350, Accessory Uses, for Additional Regulations
Accessory Dwelling Unit	See Chapter 20.350, Accessory Dwelling Units
Family Day Care Home
Small	P	P	P	P	P	See Chapter 20.350, Family Day Care Homes
Large	P	P	P	P	P
Home Occupations	P	P	P	P	P	See Chapter 20.350, Home Occupations
Temporary Uses
Temporary Use	See Chapter 20.340, Temporary Uses

Notes:
1.	Limited to facilities serving a maximum of 10 clients and may not be located within 300 feet of any other domestic violence shelter.
2.	Only on parcels with access from boulevard or connector streets.
3.	Limited to sites with a maximum gross site area of 6,500 square feet and located on a boulevard or connector street.

(Ord. 1646 § 2, 2022; Ord. 1656, 6/12/2024)

§ 20.070.003 Development Standards.

Table 20.070.003: Development Standards – Residential Zoning Districts, establishes the development standards for the residential zoning districts. The numbers in the figure below are keyed to corresponding regulations in the table. Letters in parentheses after the standards in the table refer to lettered provisions following the table.

Table 20.070.003: Development Standards – Residential Zoning Districts
Standard	RL-2.2	RL-8	RM-22	RH-37.5	RH-50	RH-180	Key
Minimum Density1	―	―	15 du/ac or existing density, whichever is greater	25 du/ac or existing density, whichever is greater	40 du/ac or existing density, whichever is greater	80 du/ac or existing density, whichever is greater
Maximum Density	2.2 du/ac (A)	8 du/ac (A)	22 du/ac (A)	37.5 du/ac (A)	50 du/ac (A)	180 du/ac (A)
Lot Size
Min. Lot Area	32,600 sf (B)	5,000 sf (B)	5,000 sf (B)	5,000 sf (B)	5,000 sf (B)	20,000 sf (B)
Min. Lot Area, Corner	32,600 sf (B)	6,000 sf (B)	6,000 sf (B)	6,000 sf (B)	6,000 sf (B)	No min. (B)
Min. Lot Width	120 ft	50 ft	50 ft	50 ft	50 ft	50 ft	①
Min. Lot Width, Corner	120 ft	60 ft	60 ft	60 ft	60 ft	―	②
Min. Lot Depth	―	80 ft	80 ft	80 ft	80 ft	―	③
Floor Area Ratio (FAR)	0.5 or 2,000 sf, whichever is greater	0.5 or 2,000 sf, whichever is greater	1.0 or 2,000 sf, whichever is greater	―	―	―
Max. Lot Coverage	40%	50%	50%	65%	65%	85%	④
Building Height
Max. Primary Building (ft/stories)	30 ft/2 stories	28 ft/2 stories (D)	35 ft/3 stories (F)	50 ft/4 stories (D)	50 ft/4 stories (D)	85 ft (D)
Max. Accessory Building	12 ft if a floor slab is used; 15 ft if floor joist construction is used
Setbacks (B)
Min. Front Setback	20 ft (B) (C)	15 ft (B) (C)	15 ft (B)	15 ft (B)	15 ft (B)	10 ft (B)	⑤
Min. Interior Side Setback	10 ft; 4 ft for SB 9 units	5 ft (H); 4 ft for SB 9 units	5 ft (F) (H)	5 for the first 2 stories; 10 ft thereafter (E) (G) (H)	5 for the first 2 stories; 10 ft thereafter (E) (G) (H)	10 ft (E) (G) (H)	⑥
Min. Street Side Setback	10 ft; 4 ft for SB 9 units (C)	10 ft; 4 ft for SB 9 units (C)	10 ft	10 ft	10 ft	10 ft	⑦
Min. Rear Setback	20 ft (I)	20 ft (I)	20 ft (F) (I)	10 ft for the first 2 stories; 15 ft thereafter (E) (I)	10 ft for the first 2 stories; 15 ft thereafter (E) (I)	0 ft (B) (E) (I)	⑧
Landscaping and Open Space
Min. Private Open Space	―	150 sf/unit	80 sf/unit	80 sf/unit	80 sf/unit	―
Min. Private Open Space Dimension	8 ft. when located on the ground level; 6 ft. when located above the ground level
Min. Common Open Space	―	―	100 sf/unit	100 sf/unit	100 sf/unit	150 sf/unit
Min. Common Open Space Dimension	20 ft.	20 ft.	20 ft.	20 ft.	20 ft.	20 ft.	⑨
Min. Landscaping	―	―	10%	10%	10%	10%

Notes:
1.	No net loss in the number of residential units during reconstruction or renovation is allowed. Replacement provisions have the same requirements as set forth in Government Code Section 65915, Subdivision (c)(3).

A. Density Bonuses. See Chapter 20.390 ("Bonus Residential Density") for additional density based on the California State Density Bonus program.

B. Hillside Lots. On lots with an average slope of 15 percent or greater, the minimum lot size and front and rear setbacks may be modified by the standards of Section 20.310.002 ("General Site and Building Design").

C. Required Daylight Planes in the RL Districts. No portion of a structure may extend above a daylight plane that is measured from a point 20 feet above average existing grade of the front or street side setback line and extending upward at a 45-degree angle.

Figure 20.070.003.C: Required Daylight Planes in the RL-2.2 District

D. Height.

1. Increased Height. Allowable height may be increased to a maximum of 35 feet with the approval of a Minor Use Permit subject to the following findings:

a. The height of the proposed structure does not exceed the average height of structures on adjoining lots;

b. The proposed structure will not substantially interfere with solar access or privacy available to residences to the side, rear, or directly across the street;

c. The design includes architectural details, articulation, and other features to minimize the visual impact of the additional bulk created by the increased height; and

d. The height, bulk, and mass of the proposed structure is comparable to that of the surrounding neighborhood.

2. Maximum Height. See Section 20.300.003 ("Airport Land Use Compatibility Plan Consistency") for airspace protection evaluation requirements based on the San Francisco International Airport Land Use Compatibility Plan.

E. Transitional Standards.

1. Where a development abuts a district with a lower maximum height, transitional height standards apply. See Section 20.310.004(B)(5) ('Transitional Standards").

2. The building setback from a district with a lower maximum height shall be 10 feet for interior side yards and 15 feet for rear yards.

Figure 20.070.003.E-2: Building Setback in an RH District When Abutting a District with a Lower Maximum Height

3. A landscaped planting area, a minimum of five feet in width, shall be provided in the RH District wherever the RH District abuts a district with a lower maximum height. Trees shall be planted in this area at a minimum interval of 15 feet.

Figure 20.070.003.E-3: Landscaped Planting Area in an RH District When Abutting a District with a Lower Maximum Height

F. Limitations on Third-Story Structures in the RM District. Third stories in the RM District are subject to the following standards

1. Any third story must be either set back a minimum of 10 feet from all interior lot lines or located inside a pitched roof with a slope of at least 1:3.

Figure 20.070.003.F-1: Limitations on Third Stories

2. Dormers are permitted on third stories, provided that they do not exceed 15 feet in width and do not occupy more than 20 percent of the total roof area.

Figure 20.070.003.F-2: Dormers on Third Stories

G. Attached Single-Unit Dwellings. Required setbacks apply only to the ends of rows of attached single-unit dwellings.

H. Reduced Side Setbacks.

1. When the existing side yard setback is less than five feet, setbacks may be extended on the ground level only and by no more than 50 percent of the existing wall length. In all instances, side yard setbacks shall be no closer than three feet to the side property line.

2. Side Yard Setback for Substandard Lots. The side yard on any lot with an average width of 50 feet or less shall be a minimum of 10 percent of the lot width, but in no case less than three feet.

I. Reduced Rear Setbacks. When the existing rear yard setback is less than 20 feet, setbacks may be extended on the ground level only and by no more than 50 percent of the existing wall length. In all instances, rear yard setbacks shall be no closer than 16 feet to the rear property line.

(Ord. 1646 § 2, 2022; Ord. 1656, 6/12/2024)

§ 20.070.004 Supplemental Standards.

A. Site and Building Design Standards. All development is subject to the standards of Chapter 20.310 ("Site and Building Design Standards") as appropriate.

B. Maximum Paving in Street-Facing Yards. No more than 50 percent of the entire front yard or the required street side yard may be covered with a paved impervious or pervious surface.

(Ord. 1646 § 2, 2022; Ord. 1656, 6/12/2024)