Kit homes/building codes

AN ACT Relating to the creation of building codes for kit homes; 1
reenacting and amending RCW 19.27.015; adding a new section to 2
chapter 19.27 RCW; creating a new section; and declaring an 3
emergency. 4
BE IT ENACTED BY THE LEGISLATURE OF THE STATE OF WASHINGTON:5
NEW SECTION. Sec. 1. The legislature finds that the price of 6
introductory housing has become unaffordable for homebuyers of modest 7
means. As a result, the legislature intends to create the kit home 8
category of building codes to provide for a small home that is 9
affordable for more homebuyers.10
Sec. 2. RCW 19.27.015 and 2024 c 170 s 9 and 2024 c 19 s 2 are 11
each reenacted and amended to read as follows: 12
As used in this chapter: 13
(1) "Agricultural structure" means a structure designed and 14
constructed to house farm implements, hay, grain, poultry, livestock, 15
or other horticultural products. This structure may not be a place of 16
human habitation or a place of employment where agricultural products 17
are processed, treated, or packaged, nor may it be a place used by 18
the public. 19
S-0715.1
SENATE BILL 5552
State of Washington 69th Legislature 2025 Regular Session
By Senators J. Wilson, Shewmake, Fortunato, Nobles, Braun, Short,
Gildon, Christian, Chapman, Holy, McCune, Warnick, Goehner, Dozier,
C. Wilson, Slatter, Cortes, Liias, Frame, Krishnadasan, and Ramos
Read first time 01/28/25. Referred to Committee on Local Government.
p. 1 SB 5552
(2) "Approval," "approved," or "adopted," unless otherwise 1
defined or otherwise indicated by context, means an affirmative vote 2
by a majority of voting members of the council, committee, or 3
advisory group present at the time of the vote. 4
(3) "City" means a city or town. 5
(4) "Commercial building permit" means a building permit issued 6
by a city or a county to construct, enlarge, alter, repair, move, 7
demolish, or change the occupancy of any building not covered by a 8
residential building permit. 9
(5) "Emergency statewide amendment" means any proposed statewide 10
amendment meeting the criteria in RCW 34.05.350. A rule shall be 11
considered an emergency rule if the council, for good cause, finds 12
that immediate adoption or amendment of a rule is necessary for the 13
preservation of the public health, safety, or general welfare, and 14
that observing the time requirements of notice and opportunity to 15
comment upon adoption of a permanent rule would be contrary to public 16
interest. 17
(6) "Kit homes" means any structures intended for residential use 18
that are comprised of prefabricated walls, floors, and roofs which 19
are assembled on-site and are 800 square feet or smaller in size.20
(7) "Model codes" means the codes developed by the model code 21
organizations and adopted by reference in RCW 19.27.031.22
(((7))) (8) "Model code organizations" means the national code-23
adopting organizations that develop the model codes, as defined in 24
this section, such as the international code council, international 25
association of plumbing and mechanical officials, and national fire 26
protection association. 27
(((8))) (9) "Multifamily residential building" means common wall 28
residential buildings that consist of four or fewer units, that do 29
not exceed two stories in height, that are less than 5,000 square 30
feet in area, and that have a one-hour fire-resistive occupancy 31
separation between units. 32
(((9))) (10) "Off-cycle amendments" means amendments to the state 33
building code outside of the three-year state building code adoption 34
cycle. 35
(((10))) (11) "Residential building permit" means a building 36
permit issued by a city or a county to construct, enlarge, alter, 37
repair, move, demolish, or change the occupancy of any building 38
containing only dwelling units used for independent living of one or 39
more persons including permanent provisions for living, sleeping, 40
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eating, cooking, and sanitation, and structures accessory to dwelling 1
units, such as detached garages and storage buildings.2
(((11))) (12) "State building code" means the codes adopted and 3
amended by the council as follows: 4
(a) The codes referenced in this chapter; 5
(b) The state energy code referenced in chapter 19.27A RCW; and6
(c) Any other codes so designated by the Washington state 7
legislature as adopted and amended by the council. 8
(((12))) (13) "State building code adoption cycle" means that 9
period during which the state building code is adopted, updated, and 10
amended by the council. 11
(((13))) (14) "Statewide amendment" means any amendment to the 12
state building code initiated through council action or by petition 13
to the council from any agency, city, county, or interested 14
individual or organization, that would have the effect of amending 15
the state building code for the entire state of Washington. A 16
statewide amendment may have a regional effect. 17
(((14))) (15) "Temporary growing structure" means a structure 18
that has the roof covered with polyethylene, polyvinyl, or similar 19
flexible synthetic material and is used to provide plants with either 20
frost protection or increased heat retention. 21
NEW SECTION. Sec. 3. A new section is added to chapter 19.27 22
RCW to read as follows: 23
(1) The state building code council is instructed to perform rule 24
making on the state building codes applicable to kit homes no later 25
than December 31, 2025. These codes must not impose costs greater 26
than $150 per square foot to the original home buyer.27
(2) The state building code council may update the state building 28
codes applicable to kit homes. However, any updates must not impose 29
costs to kit home construction exceeding $150 per square foot, 30
adjusted by the consumer price index. 31
NEW SECTION. Sec. 4. This act is necessary for the immediate 32
preservation of the public peace, health, or safety, or support of 33
the state government and its existing public institutions, and takes 34
effect immediately.35
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