The City of Seattle continues to seek public input on the environmental review of options to encourage the development of more in-law apartments and backyard cottages that would allow for more rental housing in the city’s single-family zones.
The review evaluates a proposal advanced by Councilmember Mike O’Brien that aims to remove regulatory barriers and make it easier for property owners to build Accessory Dwelling Units (ADUs).
Current City ordinances allow two types of ADUs: in-law apartments inside a single-family home and detached backyard cottages. Seattle homeowners have created 1,591 in-law apartments and 579 backyard cottages since first allowed in 1994 and 2010, respectively. Homeowners received permits to build 263 ADUs last year.
The potential policy changes analyzed through the environmental review process would increase rental housing options in areas where housing is unaffordable to most households. Since 2016, Seattle has been the city with the fastest growing single-family home prices in the nation, with the cost of the average single-family home now $820,000.
Under Seattle’s current zoning, approximately 7400 acres allow for multifamily, commercial, and mixed-use buildings, while 21,000 acres are zoned exclusively for single-family homes. There are roughly 135,000 lots in Seattle’s single-family zones.
Citywide, the rapid pace of construction in 2017 added 8,730 net new homes, most of which were apartments and townhomes. Last year, 88 percent of all new homes were built in Seattle’s urban villages. The number of detached single-family homes in Seattle remained essentially unchanged.