Seattle City Council Considering Legislation Restricting Single-Family Home Development

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The Seattle City Council is considering legislation introduced by Councilmember Mike O’Brien intended to increase the availability of affordable housing in Seattle. The proposal, which largely seeks to expand the amount of accessory dwelling units (ADUs) available in order to increase affordable housing inventory and options, would also impose new regulations on the allowable floor area ratio (FAR) in many single-family zones.

The proposed Council Bill would create new maximum limits on FAR in single-family zones.  Under the current zoning code, the available maximum size for a residence on any given single-family lot is determined by lot coverage, setback, height limit and yard size requirements. The proposed restrictions would cap the FAR for new construction single-family homes as a function of the lot size as follows:

  • New construction single-family residence on lots under 5,000 square feet would be limited to a 2,500 square foot home, exempting any below grade areas or floor areas in a designated ADU.
  • New construction single-family residence on lots of 5,000 square feet or greater would have a maximum FAR of 0.5, exempting any below grade areas or floor areas in a designated ADU. For example, a 6,000 square foot lot would allow maximum above grade floor area not dedicated to an ADU of 3,000 square feet.

While under ten percent of existing single-family houses in Seattle would not have complied with the proposed restrictions when built, nearly fifty percent of new houses built in Seattle since 2010 would have been blocked by the FAR limits in the proposed legislation. The proposal comes at a time when the development trend in Seattle has largely been to maximize square footage for new construction single-family homes, reflected by the fact that almost half of the homes built in the last nine-plus years would not have been compliant were these restrictions in place at the time.

The City Council is currently scheduled to will hold a public hearing on June 11, 2019, and the legislation could be adopted by the Council as early as June 24, 2019.

If passed, the proposed legislation would have a significant impact on the development market in Seattle. Please contact one of Helsell Fetterman’s Land Use and Real Estate attorneys with any questions or if you would like to learn more about the potential impacts of the legislation.


About the Authors

Samuel Winninghoff

Samuel is an associate in the firm's land use and real estate practice groups.

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