San Francisco — Density & Dwelling Units

District-by-District Guide

RH-1(D)

The RH-1(D) district preserves detached houses, wider lots, side yards, landscaping, and substantial front and rear open space. Dwelling units, SRO use, and student housing are listed residential uses, but the district’s physical form remains detached and low-scale (§ 209.1).

The zoning table sets the base density at up to one unit per lot, or one unit per 3,000 square feet, subject to applicable table limits and exceptions. A dwelling may not exceed 35 feet; a side yard is required on lots at least 28 feet wide, and the usual rear yard is 30% of lot depth, never less than 15 feet (§ 209.1). It applies only to parcels mapped RH-1(D); exact parcel coverage must be verified on the zoning map.

RH-1

The RH-1 district reflects San Francisco’s predominantly one-family, attached or closely spaced house pattern, often on 25-foot-wide lots. Residential uses are principal uses, while nonresidential activity is deliberately limited (§ 209.1).

The base table allows up to one unit per lot or one unit per 3,000 square feet of lot area. Dwellings generally may not exceed 35 feet, the rear yard is ordinarily 30% of lot depth with a 15-foot minimum, and required usable open space is 300 square feet private or 400 square feet common per unit (§ 209.1). Verify whether another provision, including an ADU rule, changes the parcel’s effective capacity.

RH-1(S)

The RH-1(S) district retains one-family building character while recognizing a subordinate second unit, commonly created from ground-story or storage space. The zoning table permits up to two units when the second unit is 600 square feet or less, or density based on one unit per 3,000 square feet, subject to the table’s maximum and other exceptions (§ 209.1).

The first unit receives the larger 300-square-foot private or 400-square-foot common open-space standard; the minor unit receives 100 square feet private or 133 square feet common. The district applies only where the zoning map expressly shows RH-1(S) (§ 209.1).

RH-2

The RH-2 district is intended for one- and two-family houses, commonly two large flats with separate entrances. Residential uses predominate; group housing and institutional uses may occur, but nonresidential uses remain limited (§ 209.1).

The base allowance is up to two units per lot or one unit per 1,500 square feet of lot area. Buildings are generally limited by the mapped height controls, commonly around 40 feet; the normal rear yard is 30% of lot depth with a 15-foot minimum, and usable open space is 125 square feet private or 166 square feet common per unit (§ 209.1).

RH-3

The RH-3 district accommodates one-, two-, and three-unit houses and flats, often on 25-foot-wide lots. Residential uses remain primary, but limited nonresidential uses are more common than in RH-2 (§ 209.1).

The base table permits up to three units per lot or one unit per 1,000 square feet of lot area. The ordinary rear-yard standard is 30% of lot depth, never less than 15 feet, and usable open space is 100 square feet private or 133 square feet common per unit (§ 209.1).

RM-1

The RM-1 district combines houses and lower-density apartment buildings while retaining moderate building widths, separate entrances, and substantial outdoor space. Residential uses, SROs, student housing, and limited supporting neighborhood uses are contemplated (§ 209.2).

Maximum density is one dwelling unit per 800 square feet of lot area. The rear yard is normally 30% of lot depth with a 15-foot minimum, and open space is 100 square feet private or 133 square feet common per unit (§ 209.2).

RM-2

The RM-2 district supports a broader mixture of houses and apartment buildings at moderate density. Its typical uses include dwelling units, SROs, student housing, and supporting nonresidential uses (§ 209.2).

Maximum density is one unit per 600 square feet of lot area. A rear yard of 30% of lot depth, with a 15-foot minimum, generally applies; required open space is 80 square feet private or 106 square feet common per unit (§ 209.2).

RM-3

The RM-3 district is a medium-density apartment district, commonly containing buildings with six, eight, ten, or more units, particularly near downtown. Dwelling units, SROs, student housing, group housing, and supporting nonresidential uses are characteristic (§ 209.2).

Maximum density is one unit per 400 square feet of lot area. The standard rear yard is 25% of lot depth, never less than 15 feet, while usable open space is 60 square feet private or 80 square feet common per unit (§ 209.2).

RM-4

The RM-4 district is San Francisco’s high-density residential category, characterized by apartment buildings, smaller units, taller forms, and frequent group housing near downtown. Residential and supporting nonresidential uses are contemplated (§ 209.2).

Maximum density is one unit per 200 square feet of lot area. The ordinary rear yard is 25% of lot depth, with a 15-foot minimum, and open space is 36 square feet private or 48 square feet common per unit (§ 209.2).

RC-3

The RC-3 district combines residential uses with neighborhood-serving commercial uses in a walkable, transit-oriented setting. Dwelling units, SROs, student housing, and supporting commercial uses are typical (§ 209.3).

Within an R-4 Height and Bulk District, residential density is form-based; elsewhere the maximum is one unit per 400 square feet of lot area. Front and side setbacks are not required, the rear yard is 25% of lot depth with a 15-foot minimum, and open space is 60 square feet private or 80 square feet common per unit (§ 209.3).

RC-4

The RC-4 district accommodates higher-density residential-commercial development. It allows the same broad residential-use types as RC-3, with supporting commercial activity and smaller per-unit open-space requirements (§ 209.3).

Within an R-4 Height and Bulk District, density is form-based; elsewhere the limit is one unit per 200 square feet of lot area. The Van Ness Special Use District removes the numerical density limit, while the ordinary rear-yard and open-space standards remain important unless a specific override applies (§§ 209.3, 243).

RTO-1

The RTO-1 district covers transit-served, moderate-density residential neighborhoods with houses and apartment buildings. Residential uses predominate, with small neighborhood-serving retail and services generally limited to qualifying corner lots (§ 209.4).

The zoning table establishes one unit per 600 square feet of lot area as of right and identifies greater density as requiring Conditional Use. The district ordinarily requires a rear yard of 30% of lot depth, with a 15-foot minimum, and 80 square feet private or 106 square feet common open space per unit (§ 209.4).

RTO-M

The RTO-M district applies to transit-oriented residential areas in the Mission, with multi-family housing and limited corner commercial activity. Density is form-based, so lot area does not independently cap the number of units (§§ 207(a), 209.4).

The ordinary rear yard is 25% of lot depth, never less than 15 feet, and usable open space is 100 square feet private or 133 square feet common per unit. Projects creating five or more units generally must satisfy the family-sized unit mix in § 207.6.

RTO-C

The RTO-C district combines transit-oriented housing with a wider range of neighborhood-serving commercial uses. Unlike RTO-1 and RTO-M, commercial activity is not confined to corner lots (§ 209.4).

Residential density is form-based. The ordinary rear yard is 25% of lot depth with a 15-foot minimum, and usable open space is 60 square feet private or 80 square feet common per unit; the general 10-unit bedroom-mix standard applies rather than the five-unit rule in § 207.6 (§§ 207.7, 209.4).

NCT-1

The NCT-1 Neighborhood Commercial Transit Cluster District covers small commercial clusters near major transit, generally surrounded by residential neighborhoods. It supports housing above small-scale, neighborhood-serving ground-floor retail and services (§ 750).

Density is form-based. A rear yard equal to 25% of lot depth, never less than 15 feet, applies at grade and succeeding levels; open space is 100 square feet private, 133 square feet common, or the lower amount required by the nearest Residential District (§ 750). Projects creating five or more units generally must comply with § 207.6.

Chinatown Mixed Use Districts

In the Chinatown Mixed Use Districts, maximum dwelling-unit density is the ratio stated in the specific Article 8 district table (§ 207.5(a)). The numerical ratios, individual district purposes, dimensional standards, and exact boundaries are Not found in source materials; verify the parcel’s Article 8 table.

DTR Districts

The DTR Districts impose no lot-area density limit on residential use (§ 207.5(b)). Their housing capacity is therefore determined by the applicable envelope and residential standards, and projects creating five or more units generally must satisfy § 207.6.

Individual DTR purposes, typical nonresidential uses, mapped locations, and dimensional standards are Not found in source materials. Verify the specific DTR zoning table.

Eastern Neighborhoods Mixed Use Districts

The Eastern Neighborhoods Mixed Use Districts impose no lot-area density limit on residential use (§ 207.5(c)). Housing is typically part of a mixed-use development, but the lawful count remains constrained by form-based standards and the family-sized unit requirement in § 207.6.

The complete list of Eastern Neighborhoods district designations and their parcel-level dimensional controls is Not found in source materials. Verify the applicable Article 8 table.

RCD Districts

The RCD designation is expressly subject to the five-unit family-sized dwelling mix in § 207.6. Its separate density formula, purpose, permitted-use table, mapped locations, and dimensional standards are Not found in source materials.

Van Ness & Market Residential Special Use District

Projects creating five or more dwelling units in the Van Ness & Market Residential Special Use District generally must meet one of the family-sized unit-mix options in § 207.6. Modification is available only through the procedures identified in § 309, regardless of underlying zoning (§ 207.6(d)(4)).

Other district-specific density, dimensional, use, and boundary provisions are Not found in source materials.

Polk Street Neighborhood Commercial District

The Polk Street NCD applies the family-sized mix requirement to projects creating five or more units. A modification may be sought through Conditional Use based on a unique population-serving mission or site constraints (§ 207.6).

The district’s independent density ratio and dimensional controls are Not found in source materials.

Pacific Avenue Neighborhood Commercial District

The Pacific Avenue NCD also applies the five-unit bedroom-mix threshold and allows a Conditional Use modification under the criteria in § 207.6(d)(1). Its independent density and envelope standards are Not found in source materials.

Transit-Oriented Community Minimum Densities

The minimum-density rules apply to new construction of one or more residential buildings on qualifying sites that do not already contain residential uses, unless the existing residential use will be demolished. Conversions, residential additions to existing structures, and additions on lots retaining an existing residential use are excluded (§ 207.9(b)(1)).

If multiple tiers apply, the project must meet the higher minimum. ADUs count toward the minimum, and unit fractions follow the rounding rule in § 207(b)(1) (§ 207.9(b)(2)).

TOC Tier 1

Tier 1 is the highest minimum-density category: 100 units per acre near the four specified downtown BART stations and Salesforce Transbay Transit Center. It applies only where residential use is otherwise permitted (§ 207.9).

TOC Tier 2

Tier 2 requires 75 units per acre near the 16th Street, 24th Street, Glen Park, and Balboa Park BART stations. The one-half-mile distance must use the Metropolitan Transportation Commission methodology (§ 207.9, Table 207.9).

TOC Tier 3

Tier 3 requires 50 units per acre around the listed Muni rail stops, Caltrain stations, and designated Van Ness BRT stops. This minimum does not itself waive the underlying envelope or use controls (§§ 207(a), 207.9).

TOC Tier 4

Tier 4 requires 50 units per acre near ferry terminals and in other locations made subject to § 207.9. Verify the site’s mapped qualification because the source materials do not identify every “other location.”

Housing Element Sites

Housing Element sites classified as Reused Sites or appropriate for Very Low- or Low-Income Households carry a 50-unit-per-acre minimum. A qualifying housing project reserving at least 20% of units for households at or below 80% AMI receives the by-right treatment specified in § 207.9(b)(1)(B).

A project that fails an objective minimum-density standard is non-code-compliant, but may depart through Conditional Use if the Code does not otherwise prohibit the project (§ 207.9(f)).

Required Dwelling-Unit Mix

Five-unit standard

In RTO-1, RTO-M, RCD, NCT, DTR, Eastern Neighborhoods Mixed Use Districts, the Van Ness & Market Residential SUD, and the Polk Street and Pacific Avenue NCDs, a project creating five or more dwelling units generally must choose one of these options:

• At least 40% of units contain two or more bedrooms;
• At least 30% contain three or more bedrooms; or
• At least 35% contain two or three bedrooms, including at least 10% with three bedrooms (§ 207.6).

The rule excludes projects consisting entirely of specified group housing, qualifying below-market-rate units, SRO units, student housing, or permanently designated senior or disability housing. It also excludes permits for accessory or junior accessory dwelling units (§ 207.6(b)).

General ten-unit standard

In other residential districts, applications creating 10 or more dwelling units generally must provide:

• At least 25% of units with two or more bedrooms; and
• At least 10% with three or more bedrooms (§ 207.7).

A three-bedroom unit may also count toward the two-bedroom percentage. Conditional Use may waive or modify the requirement where the project serves a unique population or physical constraints make compliance unreasonable (§ 207.7(d)).

Maximum individual unit size

The zoning tables for NCT-1 and the district represented by § 737 permit an individual dwelling unit up to the greater of 4,000 square feet of gross floor area or a 1.2:1 unit FAR. Exceeding that threshold requires Conditional Use under the cited table controls (§§ 207.10, 317, 737, 750).

For this calculation, shared spaces and common areas are excluded, as are noncontiguous accessory storage areas assigned to a unit. The calculation includes residential-building expansions permitted during the preceding 10 years and floor area constructed without a valid permit regardless of construction date (§ 207.10(f)).

Density Exceptions

Affordable units

Outside RH-1 and RH-2, and where the project is not receiving a California Government Code density bonus, on-site affordable units do not count toward maximum density when at least 20% of the project’s units qualify as Affordable Units. This exception does not waive height, bulk, or other Planning Code standards (§ 207(c)(1)).

The exemption must be documented through a recorded regulatory agreement. If affordability is not imposed through another program, the sponsor must follow the election and enforcement procedures identified in § 207(c)(1).

Affordable units in RTO districts

In an RTO District, qualifying on-site Affordable Units do not count toward density calculations and are not limited by lot area (§ 207(c)(2)).

Senior housing

Qualifying Senior Housing may be developed at up to twice the dwelling-unit density otherwise allowed in RH, RM, RC, and NC districts (§ 207(c)(3)). This is a density allowance, not a waiver of every other development standard.

Accessory dwelling units

The local and state-mandated accessory-unit programs are governed by §§ 207.1–207.2, and qualifying local ADUs receive the density treatment referenced in § 207(c)(4). Their detailed eligibility, number, placement, and state-law rules belong on the linked ADU page rather than this density reference.

Special Use District Overrides

A parcel within one of San Francisco’s Special Use Districts may have a density rule that supersedes its underlying zoning. The controlling question is whether the special section expressly replaces the base density formula or leaves it intact.

Fifth and Mission Special Use District

The Fifth and Mission Special Use District covers the area shown on Zoning Map SU01 and implements an integrated mixed-use project involving the Chronicle, Camelline, Dempster, and related downtown properties. Residential, retail, office, education, cultural, child-care, open-space, and related uses are contemplated (§ 249.74(a)–(b)).

Its residential controls are highly specific:

• Dwelling-unit density is not limited by lot area.
• Each residential building must average at least four dwelling units per residential floor.
• Each residential building must satisfy the minimum mix in § 207.6(c)(1)—at least 40% two-bedroom units under the cited option (§ 249.74(d)(3)).
• District-wide FAR may not exceed 11:1 (§ 249.74(d)(4)(D)).
• Rear-yard requirements in § 134 and ordinary dwelling-unit exposure requirements in § 140 do not apply.
• Every dwelling must instead face a public right-of-way at least 20 feet wide or an unobstructed district open area measuring at least 25 feet in every horizontal dimension at the unit’s level (§ 249.74(d)(4)(C)(ii)).
• At least 15% of required district-wide open space must be exclusively residential (§ 249.74(d)(7)(B)).

The district’s maximum building bases include 103 feet for parcels M2 and N1, and 145 feet for H1. Towers above 145 feet must satisfy specialized separation standards, including an average 75-foot separation and 100 feet between Fifth Street frontages above that elevation (§ 249.74(d)(4)).

Development applications generally require Conditional Use review under § 303, followed by consistency review against the SUD, its authorization, and the incorporated Design for Development. Ordinary discretionary-review requests are unavailable (§ 249.74(e)).

Geary Boulevard/Divisadero Street Special Use District

The Geary Boulevard/Divisadero Street Special Use District consists of Lots 5, 5A, 6, 7, 8, 9, 9A, 10, 11, and 12 in Assessor’s Block 1079. Its special controls apply to outpatient facilities operated by a health maintenance organization; other development follows the underlying zoning (§ 249.13(a)–(c)).

For qualifying HMO development:

• Residential density remains governed by the underlying zoning control table (§ 249.13(c)(5)).
• Patient rooms or beds used for outpatient treatment count as residential use for this section, regardless of length of stay (§ 249.13(c)(5)).
• The basic FAR is 6:1, but dwelling units and other defined residential uses are excluded from that FAR calculation (§ 249.13(c)(4)).
• Height and bulk designation is 105-X (§ 249.13(c)(6)).
• The Planning Commission may modify rear-yard requirements only if block open space is not harmed, comparable usable open space is provided elsewhere, and neighboring light and air are not significantly impeded (§ 249.13(c)(7)).
• A side setback of up to 15 feet may be imposed above 65 feet to secure superior architectural design (§ 249.13(c)(8)).

The district requires Planning Commission design review and a separate $15,000 application fee (§ 249.13(c)(1)–(2)).

Legalizing an Existing Unauthorized Unit

One dwelling unit constructed before January 1, 2013 without permits in an existing residential building or ancillary structure may qualify for legalization even if it exceeds district density. The building must be in a district where residential use is principally permitted, and SRO units are excluded (§ 207.3(b)(1)).

Legalization is unavailable after specified recent no-fault evictions: generally a 10-year lookback for the listed evictions and a 5-year lookback for an owner move-in eviction covered by the section, subject to its temporary-eviction exception (§ 207.3(b)(2)).

A qualifying unit:

• May exceed the district’s permitted density by one unit;
• Need not comply with rear-yard, usable-open-space, or light-and-air standards in §§ 134, 135, and 140;
• May receive a parking reduction necessary to retain the unit; and
• Must comply with all other applicable Planning Code provisions and other City codes (§ 207.3(e)–(f)).

Planning legalization does not establish building-code compliance. The unit must satisfy applicable safety requirements under the California Building Standards Code and San Francisco’s other applicable codes, with any equivalencies evaluated by the responsible agency (§ 207.3(f)).

Information Gaps

• Exact parcel boundaries for the residential and mixed-use districts are Not found in source materials. Verify the zoning map and parcel record.
• The complete Article 8 density tables for the Chinatown Mixed Use, DTR, and Eastern Neighborhoods Mixed Use districts are Not found in source materials.
• Detailed density provisions for RCD, most Neighborhood Commercial Districts, and most Special Use Districts are Not found in source materials.
• The complete substantive text of the current local and state-mandated ADU programs in §§ 207.1–207.2 is Not found in source materials.
• The full citywide applicability and modification provisions of § 207.10 are Not found in source materials beyond the supplied calculation rules and zoning-table entries.
• Parcel-specific applicability of the R-4 Height and Bulk District, TOC tiers, Housing Element site categories, and district exceptions must be verified with the jurisdiction.

Checklist

• Confirm the parcel’s base zoning district and every applicable special or overlay district.
• Read the parcel’s current zoning control table for its maximum density method.
• Determine whether density is numerical, form-based, or specially overridden.
• Exclude lot portions narrower than 5 feet and qualifying private rights-of-way from density lot area (§ 207(b)(3)–(4)).
• For split-zoned property, calculate density separately for each district portion (§ 207(b)(5)).
• Apply the one-half-or-more rounding rule (§ 207(b)(1)).
• Check whether § 207.9 imposes a 50-, 75-, or 100-unit-per-acre minimum.
• Test the project against applicable height, bulk, yard, open-space, and exposure controls.
• Apply the correct five-unit or ten-unit bedroom-mix standard (§§ 207.6–207.7).
• Determine whether an affordable-unit, senior-housing, ADU, or legalization exception applies.
• Confirm whether any requested departure requires Conditional Use authorization.
• Check project plans against applicable design review standards.
• Verify building-safety compliance separately from Planning Code density approval.

Risks & Ambiguities

Plain-English Summary

San Francisco does not determine housing capacity from lot size alone. First identify the parcel’s district: some districts impose a fixed lot-area ratio, others allow as many units as fit within the legal building envelope, and qualifying transit-area sites may require at least 50–100 units per acre (§§ 207, 207.9).

Source References

• Planning Code Article 2 — Use Districts — density provisions and district organization, including §§ 207–209.4.
• § 209.1 — RH Residential, House Districts — RH-1(D) through RH-3 density and development standards.
• § 209.2 — RM Residential, Mixed Districts — RM-1 through RM-4 density and open-space standards.
• § 209.3 — RC Residential-Commercial Districts — RC-3 and RC-4 controls.
• § 209.4 — RTO Residential Transit-Oriented Districts — RTO-1, RTO-M, and RTO-C controls.
• § 750 — NCT-1 Neighborhood Commercial Transit Cluster District — form-based density and residential standards.
• § 207.6 — district-specific minimum dwelling-unit mix — five-unit trigger and family-sized unit options.
• § 207.7 — general minimum dwelling-unit mix — ten-unit trigger and bedroom percentages.
• § 207.9 — minimum dwelling-unit densities — TOC and Housing Element minimum-density rules.
• § 207.3 — legalization of dwelling units constructed without permits — eligibility, density exception, and compliance requirements.
• § 249.74 — Fifth and Mission Special Use District — project-specific density, unit mix, exposure, FAR, and review controls.
• § 249.13 — Geary Boulevard/Divisadero Street Special Use District, including underlying density, 6:1 FAR, 105-X height and bulk, and design-review provisions.
• § 207.5 — residential density in Chinatown, DTR, and Eastern Neighborhoods Mixed Use Districts.
• § 207.10(f) — calculation of an individual dwelling unit’s gross floor area.
• Zoning Administrator interpretation associated with § 207.1 — mixed-use lot area remains available to the residential-density calculation.