Two bills attempting to regulate accessory dwelling unit (ADU) ordinances in planning cities have passed out of their originating chamber well ahead of the March 8 deadline. The stated intent of both is to provide affordable housing but neither substantively address the construction financing hurdles of building ADUs—many of which end up on short-term rental platforms because those provide the biggest return on the significant investment required to build.

SB 5235 has only had a minor amendment to clarify that it applies within urban growth boundaries only. To see the provisions of the bill, check out our first article on the bill. These requirements would take effect by the time of the city’s next comprehensive plan update, including those Puget Sound cities already under way.

Not far behind in the legislative process is an even more prescriptive and pre-emptive ADU proposal, HB 1337 (Rep. Mia Gregerson, D–SeaTac). HB 1337 applies to all GMA planning cities and those cities would have until six months after their next comprehensive plan update to comply with the changes.

The bill has not been amended since introduced but here’s a reminder of what the bill does:

• Restricts regulation of lot size, floor area ratio, setbacks, roof heights, how close the ADU can be to lot lines abutting alleys, etc.
• Requires allowing conversions from other structures and condo-izing ADUs.

In addition, cities would have to comply with at least three of the four mandates:

• Allowing at least two ADUs per lot, attached or detached or a combination.
• Not assessing impact fees more than 50% of what would have been imposed on the primary unit.
• Not requiring owner occupancy.
• Not requiring off-street parking.

The bill does allow regulating ADUs used as short-term rentals. Otherwise, applicable environmental and health and safety regulations would still apply. On the bright side, HB 1337 provides a helpful SEPA and GMA appeals safe harbor.

Date to remember

SB 5235 is scheduled for public hearing in the House Housing Committee Thursday, March 9 at 8 am.