Planning Director Bulletin No. 6: Implementing the State Density Bonus Program

This Bulletin is an overview of the State Density Bonus Law and describes the implementation procedures for projects seeking to use the program in San Francisco.

First Issued: December 2018, revised December 2025
References: California Government Code Section 65915, San Francisco Planning Code Section 206.6

‌How Does San Francisco Implement the State Density Bonus Program?

Calculating a Density Bonus – Base Density

State Law allows projects to receive up to 50% additional residential density over the maximum allowable residential density. To determine the maximum allowable residential density, Planning Department staff must calculate the principally permitted density under current controls (“base density”). Residential density regulations in San Francisco vary by zoning district. In some districts, residential density is regulated by a ratio of units to lot area, such as one unit per 600 square feet. In these districts, base density is the maximum number of units allowed by the zoning district. Other districts use “form- based density,” where residential density is regulated by the permitted building volume – either the maximum floor area ratio (FAR) or a maximum building volume controlled by height, bulk, and setback controls .

In form-based zoning districts, applicants must demonstrate that the base density can be achieved as a Code-conforming project that requires no waivers, modifications, exceptions, or variances from the Planning Code, including any applicable design standards. Applicants shall submit a “base density study”, which is a set of Code-compliant schematic plans, which shall include elevations, a building section, and floor plans for all floors, including unit layouts and unit sizes. Architectural details such as material details, will not be required for a base density study.

The Department will review these plans for compliance with the following requirements, as applicable. If the project is in a Special Use District, a Special Height and Bulk District, or other zoning or overlay district, the requirements of that district shall apply.

• Height (Planning Code Section 260)
• Bulk (Planning Code Section 270) or other applicable objective standards for upper level setbacks, including but not limited to sky plane controls in Central SoMa (Planning Code Section 249.78), upper level setbacks required along narrow streets and alleys (Planning Code Section 261.1), setbacks for sun access in Chinatown (Planning Code Section 132.3) and to public sidewalks in C-3 (Planning Code Section 146) Mid-block Alleys (Planning Code Section 270.2)
• Dwelling Unit Mix (Planning Code Section 207.6 or 207.7)
• Front Setback (Planning Code Section 132)
• Rear Yard Setback or other applicable Lot Coverage Provisions (Planning Code Section 134)
• Floor Area Ratio (FAR) (Planning Code Section 124)
• Required Commercial Uses at the Ground Floor (Planning Code Section 145.4) and Ground Floor Ceiling Height (Planning Code Section 145.1)
• Replacement of existing Production, Distribution and Repair uses, which must be shown at the ground floor of the base density study.
• Projects that propose Group Housing must include common space and common kitchens that meet the standards set forth in the Group Housing definition in Planning Code Section 102
• The following massing controls included in the San Francisco Design Standards, adopted by the Planning Commission on November 14, 2024, as applicable:
  • Setbacks Standards in Section C.2
  • Tall Buildings Standards in Section C.3
  • Modulation Standards in Section C.4
  • Lightwells and Side Setbacks Standards in Section C.5

The Planning Department applies the following provisions when calculating the base density:

The base density does not need to account for compliance with wind or shadow requirements.

• The base density study shall assume a floor-to-floor height of 9 feet, except that the ground floor ceiling height must comply with requirements set forth in Planning Code Section 145.
• In C-3 and Central SOMA Districts, a base density study may assume the use of Transferable Development Rights (TDR), however the same amount of TDR assumed in the base project must be purchased for the bonus project. In these districts, if the project seeks a waiver or incentive from floor area ratio (FAR) for its bonus project, then the sponsor need not purchase TDR for the amount of bonus Gross Floor Area (GFA) above what is assumed in the base project.
• If the bonus project includes non-residential uses, then the base density must assume the same square footage of non-residential uses in the base density study. Any non-residential uses included in the base density study shall comply with applicable objective standards, such as FAR controls.
• If a project proposes multiple buildings on one site, the base density study must include the same number of buildings as the bonus project.
• If an Accessory Dwelling Unit (ADU) can be constructed on a lot ministerially pursuant to State Law, then it may count towards the five unit minimum in the definition of Housing Development Project in CA Govt. Code Section 65915(i). ADUs that require a density waiver pursuant to Planning Code Section 207.2 will not count towards the five unit minimum. Please see Section 206.6(b) and State Law for other Density Bonus eligibility requirements. If a project is assuming more than one ADU in the base study, plans for each unit are required to confirm compliance with ADU controls. Any ADUs assumed in the base density must also be included in the bonus project.
• Commercial uses must be provided at or above the grade of the entrance at street level. Ground floor units will only be counted in the base density study if the ceiling height of that floor is at least six feet above the average grade of the site. Units provided in the basement will not be counted in the base density study. “Subterranean levels” means any floor area that is more than three feet below the average grade of the site.
• The project must show adequate circulation that meets Building and Fire Code Standards.

In cases where the Planning Code allows for increased density through a discretionary entitlement process (i.e. Conditional Use authorization), additional density achieved through the required discretionary entitlement shall not be included in the calculation of base density. For example, projects in the Residential Transit Oriented (RTO) District have a principally permitted dwelling unit density of one unit per 600 square feet of lot area but require a Conditional Use authorization to exceed one unit per 600 feet of lot area. The base density in RTO is determined based on one unit per 600 square feet of lot area.

In cases where the Planning Code requires a discretionary entitlement due to the size of the lot, and not the size and/or density of a proposed development, a project may assume maximum allowable density permitted on the lot as the base density, provided that the base density study is otherwise Code-compliant. For example, a project in a Neighborhood Commercial District (NC) that requires a Conditional Use authorization because it is located on a lot greater than 10,000 square feet may assume the maximum allowable density on a 10,000 square foot lot as the base density.

Calculating Base Density for sites that will retain existing buildings

An applicant may use the State Density Bonus on sites where there are existing buildings that will remain. An “existing building” is one that has received a Certificate of Final Completion from the Department of Building Inspection. A project must meet the definition of “Housing Development Project” of CA Govt. Code Section 65915(i) to use the State Density Bonus on a site with an existing building or buildings to be retained. A Housing Development Project is defined as a project that creates five residential units, a subdivision or common interest development, a project that substantially rehabilitates and converts an existing commercial building to a residential use, or the substantial rehabilitation of an existing multifamily dwelling, as defined in subdivision (d) of CA Govt. Code Section 65863.4, where the result of the rehabilitation would be a net increase in available residential units.

If the existing building is residential, and the property is in a form-based zoning district, the applicant must demonstrate that the site can accommodate at least five net new units within the building envelope that’s permitted under the Planning Code and applicable Design Standards. The applicant must submit a base density study that complies with the requirements of this bulletin regardless of whether the project is located in a form-based zoning district or in a district that establishes density as a ratio of units to lot area. In the base density study, the existing units may not be modified, unless they are being substantially rehabilitated as described in the Housing Development Project definition.

Example: A project site is developed with a 35-foot tall, three-story residential building with a total of six flats, and is located in a 65-foot height district. The applicant would like to construct a 30-foot tall, three story vertical addition to add more units to the building. The applicant may use the State Density Bonus Program if they can submit a base density study that shows the addition of at least five new units and complies with the requirements of this bulletin.

If the existing building is commercial or mixed use, and the bonus project only includes an addition to the existing building and does not include any conversion of non-residential to residential uses, the base density will be calculated using the remaining development potential of the subject lot. The applicant must present a base density study to show how many units can be constructed within a code-compliant addition regardless of whether the project is in a form-based zoning district or a district with density controls by lot area.

Example: a vertical addition to an existing residential building or non-residential building.

If the existing building is commercial and the project proposes to convert non-residential uses into residential uses, the applicant must submit a code-compliant base density study as if the site were vacant, except that any existing non-residential uses that the project will retain must be assumed in the base density. This methodology should also be used if an applicant proposes a project that converts non-residential uses and includes an addition to an existing building.

Example: The height limit on the project site is 200 feet. The project site is currently developed with a 100’ tall building that includes ground floor retail uses and 8 stories of office. The property owner wants to add at least 5 floors of residential uses to the site

• Scenario 1: The bonus project retains the office, and retail uses in the existing building and proposes residential uses as a vertical addition. The base density study would show a vertical addition that complies with applicable zoning controls, including bulk, height, rear yard or lot coverage, and unit mix standards.
• Scenario 2: The bonus project retains the existing building, the retail uses and three stories of office at floors 2-4 but proposes to convert the top five stories of office to residential, and to construct a vertical addition with residential uses. The base density study would assume a vacant lot, incorporating the non-residential uses at the first four floors, and then code-compliant residential uses above.

Bonus Project

The amount of additional density that a project may seek is set forth in the State Law. The maximum density bonus is an additional 50% above the base density and is based on the amount of affordable housing in the base project and the level of affordability provided in the project. To determine the percentage of density bonus allowed based upon affordable units provided, review the State Law, or consult the density bonus charts included in the Individually Requested State Density Bonus Program Supplemental Application. The maximum density bonus will be calculated as 150% of the base density represented as number of units allowed on the site, as shown in the base density study. Any fraction of unit is rounded up to the next whole number.

As set forth in CA Govt. Code Section 65915(o)(6), in form-based zoning districts, the bonus project must maintain the same average unit size and other project details from the relevant base density study, except those that may be modified by a waiver or incentive or concession to accommodate the bonus units. “Average unit size” means the average gross square footage of all of the units in the base density study or in the bonus project.

Additional Bonus

Effective January 1, 2024, AB 1287 (CA Govt. Code Section 65915(v)) allows a project sponsor to seek an additional density bonus of up to 50% in exchange for providing additional very-low income or moderate income units on site, in certain circumstances. A project that maximizes the available density bonus under CA Govt. Code Section 65915(f)(1), (2), or (4) by providing either 15% of the units at very-low income (50% AMI), 24% of the units at lower income (80%AMI), or 44% of the units at moderate income (120%AMI), is eligible to receive an additional density bonus of up to 50% in exchange for providing additional affordable units in the base project. A sponsor may receive up to a 38.75% bonus by providing up to an additional 10% of the number of units in the base project as affordable to very-low income level households. Alternatively, the sponsor may receive up to an additional 50% bonus by providing up to an additional 15% of the number of units as affordable to moderate-income households.

A project sponsor will use the same base density to calculate the additional bonus as was used to calculate the first bonus. The amount of affordable housing and the amount of density bonus will be added together. For example, a project with a base density of 100 units must provide 15% on-site affordable units, or 15 units, at very-low income to receive the maximum bonus of 50%, or 50 units. (CA Govt. Code Section 65915(f)(2); 65915(v)(1)(B)). Then, the sponsor may provide an additional 10% of the 100-unit base, or 10 additional units, as affordable to very-low income households, which qualifies for an additional bonus of 38.75%, or 39 units. (CA Govt. Code Section 65915(v)(2).) The overall bonus project will consist of 189 total units, with 25 on-site affordable units at very-low income.

In addition, under AB 1287, projects that include at least 16% of units for very-low-income households in rental or ownership projects, or at least 45% of units for moderate-income households in ownership projects are eligible for four incentives (See CA Govt. Code Section 65915(d)(2)(F).) Thus, projects that take advantage of the provisions in CA Govt. Code Section 65915(v) also may be entitled to an additional incentive. Please see the density bonus charts in the Individually Requested State Density Bonus Application on pages 5-7 for more information. Projects that provide additional moderate-income rental units under CA Govt. Code Section 65915(v)(2) are not eligible for the fourth incentive allowed under section CA Govt. Code Section 65915(d)(2) (F). The additional incentive is only available for projects that provide additional moderate-income ownership units.

Shared Housing Buildings and Shared Housing Units

State Density Bonus Law applies to “shared housing buildings” as defined in CA Govt. Code Section 65915(o)(7). A shared housing building must include common kitchens and dining areas that are “able to adequately accommodate all residents.” If a local ordinance restricts other attributes of shared housing, then the local ordinance shall apply so long as it does not conflict with the State Law.

The Planning Code definition of Group Housing sets forth additional requirements for shared housing buildings. (See Planning Code section 102.) Shared housing buildings will require one common kitchen for every 15 shared housing units, and at least 15% of the common space shall be devoted to common kitchens. A shared housing project must provide 0.5 gross square feet of common space for every square foot of private space. Although shared housing buildings must comply with the definition of Group Housing in the Planning Code, under State Law each unit in a Group Housing building using State Density Bonus law for shared housing must include a sink, refrigerator, and a microwave. No other individual or limited cooking facilities are allowed. Certain types of housing, such as student housing and 100% affordable housing, are exempt from the Planning Code’s Group Housing requirements to provide common areas and common kitchens, but must meet the requirements of State Law shared housing requirement that kitchens and dining areas adequately accommodate all residents.

100% Affordable Housing Projects

State Density Bonus Law provides a special program for 100% affordable housing projects (See CA Govt. Code Section 65915(b)(1)(G).) This program provides two alternatives for projects that, exclusive of manager’s units, provide one hundred percent of the total units must be for low or very-low income households, except that up to 20 percent of the total units in the development may be for moderate-income households.

Under the first alternative, 100% affordable projects within ½ mile of a transit stop receive unlimited density, a maximum of three additional stories in height (or 33 feet), up to five incentives or concessions, and unlimited waivers (aside from height). Projects that elect to use this alternative are not required to submit base density studies.

Under the second alternative, 100% affordable projects may seek a density bonus of 80% of the number of units for lower income households. Projects that elect this alternative are required to submit a base density study if they are located in a form-based zoning district and can ask for a waiver or incentive from height requirements

‌Other Density Bonuses

State Law also provides a density bonus for student housing, senior housing, transitional foster youth, disabled veterans, or homeless persons. A student housing project is eligible for a density bonus between 35% and 50% if 20-24% of the rental beds in the project are dedicated for lower income students. When 10% of the units in a project are devoted to transitional foster youth, disabled veterans, or homeless persons, a project may receive a 20% bonus.

A 20% bonus is also available for a senior housing development, which includes residential care facilities (RCFs). Because San Francisco considers RCFs an institutional use under the Planning Code, the density bonus would be calculated by determining the amount of principally permitted gross floor area on the subject lot, plus any allowable density bonus in gross square feet. The State Law also provides bonuses for land dedication and childcare facilities. Please see CA Govt. Code Section 65915 for additional eligibility requirements.

‌Requests for Incentives, Concessions, and Waivers

Incentives or Concessions

The State Law allows a project the right to request up to five incentives or concessions “that are required to provide for affordable housing costs.” An incentive or concession can be a reduction in site development standards, a modification of zoning code requirements, approval of mixed-use zoning, or other regulatory incentives or concessions that “result in identifiable and actual cost reductions.” The terms “incentives” and “concessions” are interchangeable; for the purposes of this document, they will be referred to simply as “incentives.”

The number of incentives the project may request depends on the number of affordable units provided and the level of affordability, as described in the table below. In addition, Student housing projects are eligible for up to two incentives.

The Project Sponsor must include the requested incentive(s) in the Individually Requested State Density Bonus Supplemental Application, along with the base density study and plans for the density bonus project. The City will approve the requested incentives unless it finds that they 1) will not result in identifiable and actual cost reductions; 2) will have specific adverse impacts on public health or safety; 3) will have specific adverse impacts on property that is listed on the California Register of Historic Resources that cannot be mitigated without rendering the development unaffordable to low-income and moderate-income households; or (4) would be contrary to state or federal law.

Project sponsors may seek up to five concessions and incentives depending on the amount of affordable housing provided and the level of affordability of those units. Verification and documentation of these cost reductions and/or impacts on public health, safety, or historic property should include a site-specific analysis. The Department may require an evaluation of the financial analysis by a qualified third-party consultant.

The following applies to any requested incentive:

1. Incentives shall be granted only from Planning Code provisions, not standards in other City regulations.
2. Except as provided in this Bulletin, a project cannot seek an incentive from any of the controls included in the Inclusionary Affordable Housing Program, including but not limited to, the Procedures Manual and Zoning Administrator Bulletin 10.
3. Incentives from a required entitlement process, any required development impact fees, or other tax assessment districts (such as Mello Roos or the Central SoMa District) shall not be allowed.

The following provisions become effective on January 1, 2026, and do not apply to projects that have submitted a preliminary application or entitlement application prior to January 1, 2026:

1. A concession or incentive shall not result in a project with a commercial floor area ratio (FAR) that is greater than 2.5 times the principally permitted commercial FAR on the project site. (See Gov’t Code Section 65915(l)(1).)
2. The City is not required to grant a concession or incentive that requires approval of, or waives development standards that apply to a tourist hotel or other transient lodging. (See Gov’t Code Section 65915(l)(2).)

Waivers

The Planning Code currently regulates the physical dimensions of residential development through requirements limiting height and bulk, or requiring open space, rear yards, dwelling unit exposure, and other requirements that may preclude the ability to construct the project with the bonus density and the requested incentives.

In accordance with the State Law, the City may not apply any development standards that will preclude the construction of the project with the bonus density or incentives within the permitted building envelope, unless the City finds that the requested waiver 1) would have a specific, adverse impact upon health or safety; 2) would have an adverse impact on any property listed in the California Register of Historical Resources that cannot be mitigated; or 3) is contrary to state or federal law.

Waivers shall be granted only from Planning Code provisions, not standards in other City regulations.

The applicant must identify the requested waivers in the Individually Requested State Density Bonus Supplemental Application and provide documentation to demonstrate that the development standard would preclude construction of the project with the additional density and the incentives.

‌Review Process

Eligibility

A project must provide at least five net new units in the base project to qualify for the State Density Bonus Program, or otherwise comply with the definition of Housing Development Project in CA Govt. Code Section 65915(i). If an ADU is required to meet the five unit minimum, that ADU must be constructed in the bonus project. The ADU will not count toward the maximum residential density with regard to required affordability or bonus calculation.

Submittal Requirements

Applicants must complete the Individually Request State Density Bonus Supplemental Application. Applicants will be required to provide a base density study and a calculation of the allowable density bonus.

The applicant must also submit plans for the bonus project that comply with the Department’s Plan Submittal Guidelines before the application will be accepted for review.

The bonus project submittal must include a description of the requested incentives and any necessary waivers, and all relevant supporting documentation. Graphic representations to support the requests for waivers are required.

Process

For projects that require a Conditional Use authorization for demolition, for a non-residential use, or because there have been residential tenants occupying the site within the last 10 years, must be approved by the Planning Commission. For projects that do not otherwise require a Planning Commission approval, the Planning Department must adopt findings that the requested incentives will result in actual cost reductions for the project, and the requested waivers and incentives will not negatively impact public health, safety, or historic property.

Regulatory Agreements

Affordable or “restricted” units provided as part of a density bonus project shall be administrated by MOHCD. Planning Code Section 206.6 requires that the applicant enter into a regulatory agreement with the City that will be recorded on the deed of the property. The agreement will include details on the number, location, and affordability of the restricted units, a description of incentives and waivers approved by the City, and other provisions to ensure compliance with Planning Code Section 206.6. A draft regulatory agreement must be approved by the Planning Department prior to the first discretionary hearing or issuance of a Planning Approval Letter, and the regulatory agreement must be finalized and recorded prior to the issuance of the site permit or building permit. Please contact the staff planner prior to the issuance of the site permit for the project to request the standard regulatory agreement template.

‌Inclusionary Affordable Housing requirements in State Density Bonus projects

San Francisco’s Inclusionary Affordable Housing Program (Planning Code section 415 et seq.) applies to the entirety of any development project with 10 or more units. Planning Code Section 415 requires a project to pay the Affordable Housing Fee on the totality of units constructed. In lieu of the Affordable Housing Fee, projects may elect to provide a percentage of units as “below market rate” (BMR) units at a price that is affordable to a specified mix of low, moderate, and middle-income households either on-site or off-site, referred to as the On-Site Alternative or Off-Site Alternative, respectively.

Projects that include on-site units to qualify for a density bonus under the State Law may also be able to satisfy all or part of the Affordable Housing Fee requirement, by receiving a “credit” for the on-site units provided. This “credit” is calculated in accordance with Planning Code Section 415.5(g)(1)(D), as part of the Combination Alternative requirement. The Combination Alternative allows projects to satisfy the Inclusionary Housing requirement through a combination of payment of the fee and provision of on-site units.

Projects may only receive a density bonus for below market rate units provided at a single income level (very low, low, or moderate income); projects cannot combine the bonuses allowed for different below market rate income levels to receive a greater density bonus, unless the project maximizes the amount of on-site affordable housing at one income level and provides additional on-site affordable housing in accordance with CA Govt. Code Section 65915(v). For example, a project cannot combine the bonus allowed for providing 5% very-low-income units (i.e. 20% bonus) and the bonus allowed for providing 10% low income units (i.e. 20% bonus), to receive a 40% bonus. However, as set forth below, a project may reduce the affordability of on-site units otherwise required by the Inclusionary Housing Ordinance.

If the base density of a site is between five and nine units, then the project is not subject to the Inclusionary Ordinance, and the sponsor may select the unit type and AMI of the required affordable units in accordance with the State Law. All on-site affordable units provided either to qualify for a density bonus under the State Law or the Inclusionary Ordinance shall be administered through the Mayor’s Office of Housing and Community Development and subject to the Inclusionary Housing Procedures Manual.

Projects that propose between 10-24 units are subject to the Inclusionary Affordable Housing Program but are subject to different rates and affordability levels than projects with 25 units or more. Projects with a base density of fewer than 24 units must comply with the small project rate and associated AMI level (55% AMI for rental and 80% AMI for ownership).

The Inclusionary Affordable Housing Program requires projects with 25 or more units that elect the On-Site Alternative to provide BMR units at three different income levels, or “tiers.” These tiers are set at different levels depending on the tenure of the proposed projects. Rental projects must provide units at 55% AMI, 80% AMI, and 110% AMI, and Ownership projects must provide units at 80% AMI, 105% AMI, and 130% AMI. Each tier is provided at a specific amount required by the Planning Code. For example, for a project application submitted in January 2024, the applicable on-site rate is 15%, comprised of 10% of the units at 80% AMI, 2.5% of units at 105% AMI, and 2.5% of units at 130% AMI. The price of a low-income ownership unit provided to satisfy the Inclusionary Program may not be reduced from 80% AMI to 50% AMI to qualify for a larger density bonus. In rental projects, the 55% AMI tier may be used to qualify for a density bonus at the very-low-income tier (50% AMI).

However, a project may request to substitute low-income units for required moderate- or middle-income Inclusionary units as an incentive. If the number of on-site Inclusionary Units exceeds the number of affordable units required under State Density Bonus Law for the requested bonus, then the remaining units shall be evenly distributed between the moderate-income Inclusionary tier (105% AMI for ownership, 80% AMI for rental) and the middle-income Inclusionary tier (130% AMI for ownership and 110% AMI for rental).

When calculating the tiers, remainders of 0.5 are rounded up unless rounding results in one more or one fewer affordable unit than required. A Density Bonus Project shall round the low-income tier (55% AMI for rental, 80% AMI for ownership) up to a whole unit from any remainder.

Projects that qualify for a density bonus by providing rental Inclusionary Units may be restricted in the ability to convert from rental to ownership in the future, and changes in tenure would require approval from the Planning Commission.

Pipeline Projects, as defined in Planning Code Section 415A.2, may apply to modify their required AMI tiers administratively through an Inclusionary Rate Reduction request.

Calculating the Inclusionary Housing Fee for Density Bonus Projects

To calculate the applicable Inclusionary Housing Fee for projects seeking a “credit” for on-site units provided to qualify for a density bonus, applicants must submit the following information:

• the number and type of on-site units to be provided, and the percentage of the total number of units in the proposed project the on-site units represent;
• documentation that all on-site units comply with the affordability levels, unit size, unit mix, unit distribution and equivalency, and other requirements of Planning Code Section 415.6 (as further specified in Zoning Administrator Bulletin No. 10), depending on the location, tenure, and number of total units in the project, and the date that the Project Application was accepted; and
• necessary AMI information to verify if/how the project qualifies for a State Density Bonus.

The remaining portion of the Fee requirement not satisfied by the credit for on-site units shall then be provided by payment of a pro-rated amount of the Affordable Housing Fee pursuant to Planning Code Section 415.5.

Rounding

For calculating the base and bonus density, the State Law requires any fractional unit to be rounded up to the next whole number. Planning Code Section 415 requires any fractional unit over 0.5 be rounded up to the next whole number. Please note these are two separate and distinct requirements. Fee calculations are rounded to the nearest cent. Ratios and percentages that are not whole numbers are rounded up to the nearest tenth.

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