Seattle Eases Accessory Dwelling Restrictions Just Ahead of State Deadline - The Urbanist

Seattle has implemented new legislation easing restrictions on accessory dwelling units (ADUs), with the reforms taking effect this week following passage in May.

The changes help the city comply with state mandates requiring local governments to reduce barriers to ADU construction.

ADUs are secondary housing units built on the same lot as a primary residence, such as converted garages, basement apartments, or detached backyard cottages.

The Seattle reforms arrive as Washington state joins California in pushing for expanded housing options to address affordability challenges.

While the specific details of Seattle's changes were not disclosed, the city indicates that broader middle housing reforms are planned for the coming months that may prove even more appealing to developers and builders.

For California property developers and homeowners, Seattle's progress illustrates the growing momentum behind ADU liberalization across the West Coast.

California has led this trend through legislation like SB 9, which allows property owners to split single-family lots and build duplexes, and various ADU reforms that have streamlined permitting and reduced restrictions.

The success of such policies in major cities like Seattle may provide additional political support for further housing reforms in California, potentially creating more opportunities for residential development and property investment in both states' increasingly expensive housing markets.