SENATE BILL REPORT
SB 5552
As of February 6, 2025
Title: An act relating to the creation of building codes for kit homes.
Brief Description: Concerning the creation of building codes for kit homes.
Sponsors: Senators Wilson, J., Shewmake, Fortunato, Nobles, Braun, Short, Gildon, Christian, Chapman, Holy, McCune, Warnick, Goehner, Dozier, Wilson, C., Slatter, Cortes, Liias, Frame, Krishnadasan and Ramos.
Brief History:
Committee Activity: Local Government: 2/06/25.
Brief Summary of Bill
  • Requires the State Building Code Council to perform rulemaking applicable to kit homes by December 31, 2025.
SENATE COMMITTEE ON LOCAL GOVERNMENT
Staff: Rohan Bhattacharjee (786-7534)
Background:

The State Building Code. The State Building Code (Code) establishes minimum performance standards and requirements for construction and construction materials in the state, consistent with accepted standards of engineering, fire, and life safety. The Code comprises a number of model codes and standards, developed and published by international and national organizations, which are adopted by reference in the State Building Code Act (Act). Model codes and standards adopted in the Act include the International Building Code, International Residential Code, the International Mechanical Code, the International Fire Code, and the Uniform Plumbing Code Standards. The State Building Code Council (SBCC) is responsible for adopting, amending, and maintaining the model codes and standards adopted by reference in the Act.

 

Kit Homes. Kit homes, also known as mill-cut houses, pre-cut houses, mail order homes, or catalog homes, are a type of prefabricated housing. These homes are constructed from a series of prefabricated components which are assembled on site. Kit homes typically do not use materials such as brick, concrete, or masonry. 
Summary of Bill:

SBCC is instructed to perform rulemaking on the Codes applicable to kit homes by December 31, 2025. These Codes must not impose costs greater than $150 per square foot to the original home buyer.

 

SBCC may update the Codes applicable to kit homes. Any updates cannot impose costs exceeding $150 per square foot to kit home construction, adjusted by the consumer price index.

 

Kit homes are defined as any structures intended for residential use comprised of prefabricated walls, floors, and roofs which are assembled on-site and are 800 square feet or smaller in size.
Appropriation: None.
Fiscal Note: Requested on February 4, 2025.
Creates Committee/Commission/Task Force that includes Legislative members: No.
Effective Date: The bill contains an emergency clause and takes effect immediately.
Staff Summary of Public Testimony:

PRO: The bill is a solution to the housing shortage. The simplicity of kit homes and their potential use as accessory dwelling units is emphasized. The urgency of addressing the housing crisis is highlighted, and a projected shortfall of one million homes over 20 years is cited.

 

CON: The bill's definition of kit homes lacks specificity, creating ambiguity about materials and components. The bill's cost cap of $150 per square foot is concerning, which could undermine building safety and health codes. Additionally, the importance of the State Building Code Council’s role in ensuring safe and enforceable regulations is emphasized.

 

OTHER: There are challenges in ensuring long-term compliance with safety standards, particularly for kit homes manufactured out of state. Inspectors typically check homes once after construction, making it difficult to ensure compliance over decades. Clarity is necessary on cost control and long-term safety enforcement while recognizing the potential of kit homes to address housing needs.
Persons Testifying: PRO: Senator Jeff Wilson, Prime Sponsor.
CON: Tammie Sueirro, AIAWA (American Institute of Architects WA Council).
OTHER: Tim Woodard, Washington Assn. of Building Officials (WABO) .
Persons Signed In To Testify But Not Testifying: No one.