Regional Building Codes for Factory-Built Structures

The act provides that, after the state housing board (board) adopts rules about any activity required to undertake or complete the construction or installation of a factory-built nonresidential structure, a factory-built residential structure, or a factory-built tiny home (factory-built structure), the state plumbing board, the state electrical board, and the state fire suppression administrator do not have jurisdiction over and their rules do not apply to a factory-built structure.

The advisory committee on factory-built structures and tiny homes (advisory committee) is required to develop regional building codes standards accounting for local climatic and geographic conditions and fire suppression activities to ensure safety, to apply the most stringent of these requirements for the construction and installation of factory-built structures, and to develop implementation requirements. The advisory committee must submit the recommended codes and implementation requirements to the board. Any future statewide adopted codes contemplated in statute must be vetted through the advisory committee for consideration for adoption by the board.

The act requires that plumbing or electrical installations that connect factory-built structures to external utility sources and that are not considered actions to complete the installation of a factory- built structure as required by a registered installer must be completed by a licenced plumber or electrician under a registered plumbing or electrical contractor. The inspection and inspectors of these installations, other than those authorized to be performed by a registered installer, must be performed by licensed plumbing or electrical inspectors.

During the 2026 legislative session, the department of local affairs (department) shall present the recommendations of the advisory committee related to the development of regional building codes accounting for local climatic and geographic conditions and fire suppression activities, and improved coordination between the state and local permitting process onsite for the construction and installation of factory-built structures, to the senate local government and housing committee and the house transportation, housing, and local government committee prior to consideration and adoption by the board. The department shall report on the outcomes as part of its 2031 "SMART Act" hearing.

On or before July 1, 2026, the board must adopt rules:

• Establishing regional building code standards from the advisory committee that account for local climatic and geographic conditions, and fire protection and suppression activities for the construction and installation of factory-built structures developed by the advisory committee, which supersede any conflicting ordinance, code, regulation, or other law of a local government unless the local government adopts the rules of the board;
• Establishing requirements based on the recommendations developed by the advisory committee, including the continued authorization of a local government certified by the division of housing (division) to perform inspections of factory-built structures on behalf of the division and registration, responsibility, and accountability requirements for a manufacturer, installer, seller, or general contractor who develops the installation site or completes the construction of a factory-built structure at the installation site;
• Covering electrical or plumbing codes required to undertake or complete the construction or installation of a factory-built structure;
• Allowing the division to contract for third-party review and approval of a final design and construction plan for a factory-built structure on behalf of the division;
• Allowing the division to create a process for vetting and approving the ability of a third party to review and approve a final design and construction plan for a factory-built structure on behalf of the division; and
• Requiring the division to cause an audit to be performed on a third party that reviews and approves design and construction plans, on a third party that conducts inspections on its behalf, of contracts of sellers to verify compliance, and to ensure protection of down payments made by purchasers that are retained by the seller of manufacturer.

A county or municipality may not:

• Enact a regulation that excludes factory-built structures from the county or municipality;
• Impose more restrictive standards on factory-built structures than those that the county or municipality applies to site-built homes in the same residential zones in the county or municipality; or
• Enact or enforce a regulation, law, or ordinance affecting the installation or construction of a factory-built structure that is more stringent than a regulation, ordinance, or law that applies to other types of construction.

A county or municipality may enact:

• Land use regulations to the extent that the regulations are applicable to existing similar housing or structures or new site-built housing in the county or municipality;
• A building code provision for unique public safety requirements unless the provision applies to a factory-built structure; and
• Rules regulating above-grade site-built components of a factory-built structure.

Factory-built homes certified by the division prior to the effective date of the regional building code standards adopted by the board are subject to state or local rules concerning unique public safety requirements related to geographic conditions or wildfire risk relating to the construction and installation of the structures existing before the effective date of the regional building code standards. A county or municipality must comply with the requirements established by the division for factory-built structures and by the United States department of housing and urban development for manufactured homes.

The act repeals the ability of local governments to adopt different standards for factory-built housing than those adopted by the division only if:

• The board adopts rules establishing requirements for factory-built housing based on the recommendations of the advisory committee; and
• The board notifies the revisor of statutes in writing via email of the adoption of the rules. The act changes the composition of the advisory committee from 15 to 19 members. The membership changes include the:
• Addition of four members from building code enforcement, each representing a local building department from climate zones 4, 5, 6, and 7, instead of 3 members from building code enforcement;
• Removal of a member with experience in mechanical engineering or contracting;
• Substitution of a member who is a licensed electrician who may be employed by the department of regulatory agencies for a member from electrical engineering or contracting;
• Substitution of a member who is a licensed plumber who may be employed by the department of regulatory agencies for a member from the plumbing industry;
• Removal of a member from the construction design or producer industry;
• Substitution of 3 members from factory-built structure construction for 2 members from manufactured housing;
• Subtraction of one of the 2 current members from the tiny home industry;
• Addition of one member who is a developer specializing in the use of factory-built structures in projects;
• Addition of one member from climate resiliency;
• Addition of one member who is a registered installer;
• Addition of one member who is a registered seller; and
• Addition of one member who is an individual representing emergency services or management.

The state treasurer shall transfer $600,000 on July 1, 2025, from the innovative housing incentive program fund to the building regulation fund. The act excludes the building regulation fund from the limitations on cash fund reserves.

For the 2025-26 state fiscal year, the act appropriates $182,264 from the building regulation fund to the department for use by the division to implement the act.

(Note: This summary applies to this bill as enacted.)