Key Dates

What: Middle Housing & ADU Code Amendments Public Hearing

When: April 29, 2025 at 5:30 p.m.

Where: City Council Chambers at SeaTac City Hall, 4800 S 188th St., SeaTac

PROJECT DESCRIPTION 

The City is proposing amendments to the SeaTac Zoning Code related to middle housing and accessory dwelling units (ADUs). The intent of these revisions is to adhere to the requirements of HBs 1110 and 1337, which require all cities planning under the Growth Management Act (GMA) to make certain changes to codes and development regulations to allow middle housing and ADUs, no later than June 30, 2025. In addition to the proposed middle housing/ADU-related amendments, this package includes remaining code clean-up amendments related to Envision SeaTac 2044. 

What is middle housing?

Washington State defines middle housing, in the Growth Management Act (GMA), as “…buildings that are compatible in scale, form, and character with single-family houses and contain two or more attached, stacked, or clustered homes including duplexes, triplexes, fourplexes, fiveplexes, sixplexes, townhouses, stacked flats, courtyard apartments, and cottage housing.” These residential developments are more dense than single-family housing and less dense than typical midrise apartment buildings, but similar in scale to single-family homes.

Find more information on middle housing and ADU code updates here.

Staff contact: Laura Stilwell, Associate Planner, by email at lstilwell@seatacwa.gov or by phone at (206) 973-4833.