Two New Washington State Laws Are Designed to Increase Housing Density

The Washington State Legislature recently approved two new laws designed to increase housing density. Both laws will go into effect on July 23, 2023. The first law requires cities with over 25,000 people to allow at least duplexes in all areas and cities with more than 75,000 people to allow at least fourplexes in all areas. Community associations whose governing documents contain more restrictive housing provisions as of that date are exempt from those requirements, but they are prohibited from amending their governing documents to prohibit duplexes and other kinds of middle housing after that date. The second law states in part that the governing documents of community associations created after that date that are within an urban growth area may not impose any restriction or prohibition on the construction, development, or use on a lot of an accessory dwelling unit that the city or county where that area is located would be prohibited from imposing under that law. Those prohibited impositions are described in the new law as follows: 

(a) The city or county may not assess impact fees on the construction of accessory dwelling units that are greater than 50 percent of the impact fees that would be imposed on the principal unit;

(b) The city or county may not require the owner of a lot on which there is an accessory dwelling unit to reside in or occupy the accessory dwelling unit or another housing unit on the same lot;

(c) The city or county must allow at least two accessory dwelling units on all lots that are located in all zoning districts within an urban growth area that allow for single-family homes in the following configurations:

(i) One attached accessory dwelling unit and one detached accessory dwelling unit;

(ii) Two attached accessory dwelling units; or

(iii) Two detached accessory dwelling units, which may be comprised of either one or two detached structures;

(d) The city or county must permit accessory dwelling units in structures detached from the principal unit;

(e) The city or county must allow an accessory dwelling unit on any lot that meets the minimum lot size required for the principal unit;

(f) The city or county may not establish a maximum gross floor area requirement for accessory dwelling units that is less than 1,000 square feet;

(g) The city or county may not establish roof height limits on an accessory dwelling unit of less than 24 feet, unless the height limitation that applies to the principal unit is less than 24 feet, in which case a city or county may not impose roof height limitation on accessory dwelling units that is less than the height limitation that applies to the principal unit;

(h) A city or county may not impose setback 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;

(i) A city or county must allow detached accessory dwelling units to be sited at a lot line if the lot line abuts a public alley, unless the city or county routinely plows snow on the public alley;

(j) A city or county must allow accessory dwelling units to be converted from existing structures, including but not limited to detached garages, even if they violate current code requirements for setbacks or lot coverage;

(k) A city or county may not prohibit 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; and

(l) A city or county may not require public street improvements as a condition of permitting accessory dwelling units.

(2)(a) A city or county subject to the requirements of this section may not:

(i) Require off-street parking as a condition of permitting development of accessory dwelling units within one-half mile walking distance of a major transit stop;

(ii) Require more than one off-street parking space per unit as a condition of permitting development of accessory dwelling units on lots smaller than 6,000 square feet before any zero lot line subdivisions or lot splits; and

(iii) Require more than two off-street parking spaces per unit as a condition of permitting development of accessory dwelling units on lots greater than 6,000 square feet before any zero lot line subdivisions or lot splits.

(3) When regulating accessory dwelling units, cities and counties may impose a limit of two accessory dwelling units, in addition to the principal unit, on a residential lot of 2,000 square feet or less.