New Zoning Law on Accessory Dwelling Units (“ADUs”) – Washington State HB 1337 – How Does It Affect Me?
New legislation in Washington state drastically changes zoning for most single-family neighborhoods. This piece covers one of the most impactful statutes, House Bill 1337.
In much of Washington, housing is expensive, and inventory is very tight. In response, the Washington legislature recently enacted HB 1110 and HB 1337. HB 1110 – discussed in detail by my partner, Babak Shamsi, here and here – expands density via compelled zoning approval of multiplexes. At issue in this post is HB 1337, which further expands density through compelled approval of accessory dwelling units (“ADUs“), effective July 23, 2023.
An “ADU” is a dwelling unit located on the same tax lot as a principal unit. “Principal unit” means the single-family housing unit, duplex, triplex, townhome, or other housing unit located on the same lot as an accessory dwelling unit. An ADU can be physically attached to the principal unit or detached from the principal unit.
What does HB 1337 do?
HB 1337 requires the adoption or amendment of municipal zoning regulations to allow for at least two ADUs on all lots located in all zoning districts within an urban growth area that allow for single-family homes. HB 1337 supersedes and preempts all municipal zoning regulations failing to abide by its terms. Municipalities must adopt, amend, and incorporate HB 1337 into their land use regulations to become effective within six months after the respective municipalities’ next periodic comprehensive plan update as required by RCW 36.70A.130. This means that the vast majority of homeowners in Washington state will be entitled to construct ADUs on their lots despite their current local zoning law. Homeowners may construct ADUs from the ground up, or from existing structures such as detached garages, even if they violate current code requirements for setback or lot coverage. Importantly, this opens the door to additional, viable streams of income for homeowners and provides additional availability of affordable housing.
Specifically, HB 1337 prohibits municipalities from (1) requiring the homeowner to reside in or occupy any housing unit on the same lot; (2) assessing impact fees on the construction of ADUs greater than 50% of the impact fees imposed on the principal unit; (3) establishing height limits less than 24 feet, unless the height limitation upon the principal unit is less than 24 feet, in which case the height limitation upon the ADU will be limited to that of limitation upon the principal unit; (4) imposing set-back requirements, yard coverage limits, tree retention mandates, restrictions on entry door locations, aesthetic requirements, or requirements for design review for accessory dwelling units that are more restrictive than those for principal units; (5) prohibiting the sale or other conveyance of a condominium unit independently of a principal unit solely on the grounds that the condominium unit was originally built as an accessory dwelling unit; (6) requiring public street improvements as a condition of permitting ADUs; and (7) requiring certain parking restrictions; amongst a few other limitations.
However, HB 1337 continues to entitle municipalities to (l) restrict the use of ADUs to prevent short-term rentals; (2) apply environmental permitting requirements that would be otherwise applicable to the principal unit; and (3) prohibit ADU construction not connected to or served by public sewers, amongst a few others. While municipalities may restrict ADUs subject to the above, HB 1337 greatly expands the acceptability of ADUs in most instances.
Considerations
The moral of the story: the Washington legislature has expanded housing options through ADUs, largely preventing municipalities from restricting such ADUs. Whether you are a homeowner looking for another stream of income, or a renter looking for affordable housing, HB 1337 opens many doors.
If you are interested in constructing an ADU, or you have any questions about the applicability of HB 1337and how it applies to you, please call (425) 776-4100, or email info@beresfordlaw.com.
