Residential Expansion Threshold

A clear process for alterations.

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Residential Expansion Threshold: A clear process for alterations and demolitions
If you would like Planning staff to attend an upcoming neighborhood or organization meeting, please contact



Beginning in 2005, the Planning Department began to look at project applications that weren’t proposing to demolish entire properties, but were proposing to remove a significant portion of the building. These projects were not subject to Planning Commission review as they were not classified as “demolitions” as defined by the Department of Building Inspection (DBI).

To address this, legislation was finalized in 2007 to create regulations on demolitions of existing housing and what is currently known as “Tantamount to Demolition.”  As a result, any project application that is considered Tantamount to Demolition is reviewed no different than a formal demolition project and will typically receive additional scrutiny from the Planning Commission.  

What is “Tantamount to Demolition”?

Any project application that proposes one or more of the following criteria is considered “Tantamount to Demolition” and subject to San Francisco Planning Code Section 317.

  • A major alteration of a residential building, removing more than 50 percent of the front and rear façade (combined); and
  • Removing more than 65 percent of all exterior walls or
  • A major alteration of a residential building removing more than 50 percent of the Vertical Envelope Elements (defined as all exterior walls that provide weather and thermal barriers between the interior and exterior of the building, or that provide structural support to other elements of the building envelope); and
  • More than 50 percent of the Horizontal Elements (defined as all roof areas and all floor plates, except floor plates at or below grade) of the existing building, as measured in gross square feet of actual surface area

Changing Policies and Design Review

In 2005, the Department began requiring mandatory review for alterations that modified properties considered a “potential historic resource” (also known as Category B Buildings) to help preserve the architectural features that contribute to neighborhood character. In 2009, the Department introduced an improved design review process, requiring most residential projects to undergo a formal design review with the Residential Design Team. (Find more information on the Residential Design Guidelines here.) These combined efforts have resulted in consistent project reviews to better ensure neighborhood compatibility.

Eliminating Tantamount to Demolition

The current controls have led to project sponsors designing just short of the threshold, with these results:

  • Allowing major additions. A project can significantly expand the size of the existing housing while still meeting the Tantamount to Demolition threshold, thus be approved administratively (no Commission hearing required).
  • Potential for inferior design.

The Department agrees with the public that Tantamount to Demolition is not effective in respecting neighborhood character.


In keeping with the ongoing effort of changing practices to better meet the needs of the City, the Department is proposing to remove the Tantamount to Demolition calculations from the Planning Code and replace them with a standard that would limit the size of the finished project to be more consistent with neighborhood character.  The Department believes that limiting the overall size of a single family home can ultimately help balance the character of the neighborhood with a property owner’s rights to improve and expand their property. This new standard will provide clarity for both project sponsors and their neighbors and will streamline the overall process; effectively saving time for both sponsors and staff.

These proposed changes do not affect any policies related to the review of mergers or proposed demolitions of any units under rent control.

The intention behind Section 317 is to address the ongoing shortage of affordable housing.  The Department recognizes projects that are currently designing to the Tantamount to Demolition thresholds are not more affordable, and as such the Department is proposing to separate the policy issue of large alterations from the preservation of existing housing.  As part of this effort, projects that would be subject to this new threshold would be reviewed in a new code section.

Proposed Changes

These changes are not final and still being discussed. We invite the community to contribute to the conversation so that the final proposal recognizes the priorities of San Francisco residents (sign up to Get Project Alerts to stay informed).

Draft Proposal

Proposed projects requiring a Planning Commission hearing:

  • Any project that will demolish one or more rent controlled units (This is a current requirement. In 2015, Supervisor Avalos introduced legislation to require Commission review and a Conditional Use Authorizationto remove any unit, legal or unauthorized, helping maintain our existing housing stock through increased safeguards.)
  • Any project that will, through demolition and new construction, or, through a large alteration, result in a unit that is more than 3,000 GSF. (Process yet to be determined)

Proposed projects that qualify for Administrative Approval: (no Commission hearing required)

  • Any project that uses all of its principally permitted density and keeps all units below 3,000 GSF
  • If a proposed project’s existing building already exceeds 3,000 GSF as of the date the ordinance took effect, then the project would be permitted to add up to 500 square feet before requiring a Mandatory Discretionary Review (process yet to be determined).

Community Feedback

Staff would like to hear more from the community about the proposed changes to the Code on any number of topics, including but not limited to:

  • Is 3,000 GSF for a single family home the right size to trigger Commission review? Should it vary by neighborhood or district?
  • What criteria should the Commission consider for the projects that do require their review?
  • What about projects that propose excavation?
  • Public comment proposals to date.

Get in touch with our Contact if you would like Planning staff to attend an upcoming neighborhood or organization meeting, please contact at .


  • August 31, 2016: First informal meeting with community members
  • September 22, 2016:  Informational presentation to the Planning Commission
  • September – October, 2016: Community Conversation on Proposed Changes October 12, 6-8pm at Planning Department, 1650 Mission Street, Room 431
  • October 4, 2016: Meeting with architects (open to the public) Noon-1pm at Planning Department
  • October 12, 2016: Community Meeting, 6:00 - 8:00 p.m. at Planning Department 
  • October 27, 2016: Informational presentation and update to the Planning Commission