A bill passed by the Washington state Senate this week could make small manufactured kit homes a more common option for affordable housing.
Nineteenth Legislative District state Sen. Jeff Wilson, R-Longview, presented one of two bills he is sponsoring this session concerning kit homes to the Washington state House of Representatives Local Government Committee on Wednesday morning, urging members to advance Senate Bill 5552. The legislation calls for the state’s Building Code Council to create building codes for small kit homes.
Wilson also sponsored Senate Bill 5249 during this year's legislative session, which would have allowed local governments more freedom in zoning and permitting small kit homes for temporary and emergency use, for example as transitional or shelter housing. That bill will not advance any further this session. After making it out of committee, it was not taken up by the Senate ahead of a Tuesday evening deadline that required bills be passed by their house of origin to stay active this session.
Wilson's sponsorship of the two bills continues a years-long effort by the senator to urge a focus on making kit homes a more viable option for addressing the state's housing supply shortages.
“Due to our housing crisis, this is just another option that will add to the menu of choices,” Wilson said during the Wednesday morning public hearing on SB 5552.
The senator first introduced both bills in the 2025 legislative session after previously sponsoring similar legislation. Neither made it to the governor's desk last year, but this year, with Gov. Bob Ferguson emphasizing a focus on housing supply ahead of the session, Wilson hopes SB 5552 can go the distance.
Senate Bill 5552
Wilson insists the Legislature has advanced the better of the two bills. According to the senator, SB 5552, which received its public hearing Wednesday morning and is already scheduled for an executive session in the committee later this week, could help make kit homes a more likely permanent housing option.
“With starter homes being incredibly expensive, I certainly don't know if I could begin to start over again in today's times,” Wilson said. “And kit homes (are) a concept that is so affordable. I dare say it's almost impossible to find another more affordable type of home.”
The bill is relatively simple. The summary of the bill included in the most recent legislative analysis is just two sentences. It first defines kit homes in this context as homes 800 square feet or smaller and made up of premanufactured parts — walls, floors and roofs — that are assembled on site.
It then mandates that the Washington Building Code Council complete rulemaking on the state's building codes applicable for the small kit homes no later than March 31 of next year. In his testimony on the bill Wednesday morning, Wilson added that conversations with building code council staff suggested they may complete the rulemaking sooner than mandated.
The Senate passed SB 5552 early in the session, long before any cutoff deadlines that could have ended its progress. It made it just as far in the 2025 session before stalling out and failing to receive a vote on the floor of the House.
That could still happen this session, but according to Wilson, this year is different, not only because of the governor's open support for more affordable housing options, but also because Wilson has narrowed the scope of the bill. The original version of the bill set a limit on the cost per square foot that state codes could impose on kit homes, but that stipulation is gone from the most current version of the bill.
Testimony during last year's session from the American Institute of Architects cited concerns that capping the cost imposed on someone building a kit home at $150 per square foot could impact safety by limiting what work or safety requirements could be imposed.
Senate Bill 5249
Wilson's other kit home bill, Senate Bill 5249, he says may need more work to get over the finish line. While some would label it as “dead” since it is not advancing any further this session, Wilson has not given up on it yet, hinting he may continue to push the policy in future sessions.
The bill makes allowances for local governments, such as cities and counties, to use kit homes for temporary emergency housing, as many already do. But it adds stipulations that the structures be inspected every five years to meet certain safety and living standards. In this bill, the definition of a kit home is the same as in SB 5552 and refers to homes of 800 square feet or less that are built on site out of premanufactured walls, roofs and other structural elements.
The bill requires the five-year inspections by mandating local governments to pass an ordinance to construct the temporary kit homes that includes a plan for five-year check-ins.
In a brief interview with the senator on Wednesday, he said he was concerned with the definition of emergency and temporary shelters already being used and that local governments may not be obligated to ensure that the shelters are still fit for living.
“There are several bills already throughout the state that are somewhat tied into, say, providing kid or pallet shelters for homeless communities,” Wilson said. “The problem with that is, how long is temporary supposed to last for? How long is an emergency supposed to last for?”
Many communities in the state are already using tiny home villages as a form of transitional housing for people experiencing homelessness. One such village exists just north of Lewis County in Olympia and one is set to come online soon in Centralia, known as Shalom Village.
This session, the Senate Ways and Means Committee signed off on the bill and sent it to the floor of the Senate, but it was passed over there in favor of other bills.
