This bill aims to address the growing issue of housing affordability by establishing a new category of building codes specifically for "kit homes." Kit homes are defined as residential structures that are 800 square feet or smaller, made up of prefabricated walls, floors, and roofs that are assembled on-site. The legislation includes amendments to existing definitions in RCW 19.27.015, such as the insertion of the definition for "kit homes," which is intended to facilitate the construction of affordable housing options for homebuyers of modest means.

Additionally, the bill mandates that the state building code council undertake rule-making for the state building codes applicable to kit homes by March 31, 2027, and allows for updates to these codes as necessary. This initiative reflects the legislature's commitment to improving housing accessibility and affordability in Washington State, particularly for those who may struggle to enter the housing market.