Developing Small Single-Family Lots - Accomplishments

Project Outcomes

The small lot development ordinance (Ordinance 124475) was adopted by the City Council on May 19, 2014 and signed by the Mayor on May 29. The small lot ordinance went into effect on June 28, and applies to building permit applications submitted after that date.

Some of the changes made by the ordinance include:

  • The lot area exception for historic lots (of record before 1957) has been narrowed. Lots under 2,500 square feet no longer qualify for an exception, and lots may no longer qualify based on historic tax or mortgage records.
  • New development on lots under 3,200 square feet in area now requires a “special exception.” This process includes public notice and an opportunity to appeal to the City Hearing Examiner.
  • Houses on lots under 3,200 square feet (based on the largest rectangular area within the lot lines) are limited to 18 feet in height, plus five feet for a pitched roof. Additional height is allowed where houses on neighboring lots are taller. An exception is provided for additions to existing homes, of up to 1,000 square feet or the area of one floor, whichever is more.
  • A special provision for short subdivision of lots developed with more than one house has been eliminated. Ownership of the houses may now be divided using the unit lot subdivision process.
  • The “75/80 Rule” lot area exception was modified and clarified, in part to better address how it applies when lots have frontage on multiple streets. Large lots developed with uses other than single-family homes, such as schools and churches, do not need to be considered when determining whether a proposed lot is at least 80 percent as large as the other lots on the block.

Key Milestones 

  • September 2012
    City Council adopted Ordinance 123978 as interim regulations for small-lot development in single-family zones
  • November 2012
    DPD hosted a public meeting about the proposed changes
  • March 2013
    DPD presented preliminary recommendations to the City Council
  • May 2014
    City Council Adopted Ordinance 124475 putting in place permanent regulations for small-lot development in single-family zones
  • June 2014
    The small lot ordinance went into effect on June 28, 2014

Project Purpose

  • New construction in our neighborhoods will better meet the needs of current residents as well as new residents
  • Owners who acquired a property before the adoption of the new requirements will maintain a reasonable opportunity to benefit from their investment
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Address: 700 5th Ave, Suite 2000, Seattle, WA, 98104
Mailing Address: P.O. Box 34019, Seattle, WA, 98124-4019
Phone: (206) 684-8600
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SDCI issues land use, construction, and trade permits, conducts construction and housing-related inspections, ensures compliance with our codes, and regulates rental rules. SDCI is committed to an antiracist workplace and to addressing racism through our work in the community.