How do I calculate the allowed building size under FAR rules?

Multiply your lot size by the Floor Area Ratio (FAR) of 3.60 to get your max allowable floor area.

What is the required rear yard in RM-3?

You need at least 15.00 feet at the rear of your property.

Can I build an ADU (Accessory Dwelling Unit) in this zone?

Yes. ADUs are permitted in RM-3. Refer to the latest state and local ADU guidelines for placement and design standards.

California > San Francisco County > San Francisco > RM-3

RM-3 (Residential, Mixed Districts, Medium Density)

San Francisco, California

Jump to Zoning Use Permissions

Basic Information

Zone Type	Residential
Code Section	209.2
Code URL	View Code

Dimensional Standards

Height Notes	Varies; See Map

Density

Min Units per Lot	3.00
Base Density (sqft/unit)	533.00
Max Density (sqft/unit)	400.00
Density Notes	P if 3 units per lot or at least one unit per 533 square feet of lot area, whichever is greater. Total maximum permitted density is one unit per 400 square feet of lot area
Floor Area Ratio (FAR)	3.60

Setbacks

Front Setback Notes	Based on the front setback of the adjacent property with the shortest front setback or if subject property has a Legislated Setback. When front setback is based on adjacent properties, in no case shall the required setback be greater than 10 feet.
Rear Setback (ft)	15.00
Rear Setback Notes	25% of lot depth, but in no case less than 15 feet.
Side Setback Notes	Not Required

Parking

Parking Notes	Maximum permitted per § 151.

Usable Open Space

Private Open Space (sqft/unit)	60
Common Open Space (sqft/unit)	80

ADU and SB9 Eligibility

ADU Allowed	Yes
ADU Notes	Construction of Accessory Dwelling Units may be permitted pursuant to Sections 207.1 and 207.2.

Example and Description

Detailed Description	These Districts have some smaller structures, but are predominantly devoted to apartment buildings of six, eight, 10 or more units. Most of these districts are close to downtown and have been developed in this manner for some time. The units vary in size, but tend to be smaller than in RM-1 and RM-2 Districts. Many buildings exceed 40 feet in height, and in some cases additional buildings over that height may be accommodated without disruption of the district character. Although lots and buildings wider than 25 or 35 feet are common, the scale often remains moderate through sensitive fa ç ade design and segmentation. Open spaces are smaller, but decks and balconies are used to advantage for many units. Supporting nonresidential uses are often found in these areas.

Detailed Description

These Districts have some smaller structures, but are predominantly devoted to apartment buildings of six, eight, 10 or more units. Most of these districts are close to downtown and have been developed in this manner for some time. The units vary in size, but tend to be smaller than in RM-1 and RM-2 Districts. Many buildings exceed 40 feet in height, and in some cases additional buildings over that height may be accommodated without disruption of the district character. Although lots and buildings wider than 25 or 35 feet are common, the scale often remains moderate through sensitive fa ç ade design and segmentation. Open spaces are smaller, but decks and balconies are used to advantage for many units. Supporting nonresidential uses are often found in these areas.

Zoning Use Permissions

P = Permitted

C = Conditional

NP = Not Permitted

Use Category	Permission Type	Notes
Agricultural Uses	C
Agriculture, Industrial	NP
Agriculture, Neighborhood	P
Automotive Uses	NP
Awning	P	P for Limited Commercial Uses and Limited Corner Commercial Uses per § 136.1 only, otherwise NP.
Canopy or Marquee	NP
Child Care Facility	P
Community Facility	C
Entertainment, Arts and Recreation Uses	NP
Homeless Shelter	P
Hospital	C
Hotel	C	C for 5 or fewer guest rooms or suites of rooms; NP for 6 or more guest rooms; provided, however, that a total of up to 47 Tourist Hotel rooms are Principally Permitted on Block 0976, Lot 001, subject to the provisions of Ordinance No. 251-22.
Industrial Uses	NP
Institutional Uses	NP
Intermediate Length Occupancy	P	NP for buildings with three or fewer Dwelling Units; C for buildings with 10 or more Dwelling Units.
Internet Service Exchange	C
Mortuary	C	Must be located on a landmark site, and where the site is within a Height and Bulk District of 40 feet or less, and where a columbarium use has lawfully and continuously operated since the time of designation.
Non-Retail Sales and Service	NP
Open Recreation Area	C
Parking Garage, Private	C
Parking Lot, Private	C
Passive Outdoor Recreation	P
Planned Unit Development	C
Post-Secondary Ed. Institution	C
Public Facilities	P
Religious Institution	C
Residential Care Facility	P
Residential Density, Group Housing	P	C required if the Group Housing is affiliated with and operated by a Hospital or an Institutional Educational Use as defined in Section 102.
Retail Sales and Service Uses	NP
School	C
Single Room Occupancy	P
Student Housing	P
Utility and Infrastructure	NP
Utility Installation	C
Wireless Telecommunications Services Facility	P or C	C if a Macro WTS Facility; P if a Micro WTS Facility.