In 1974, the United States had three model building codes with many state and local modifications. That year, Congress passed the National Manufactured Housing Construction and Safety Standards Act (42 U.S.C. § 5401 et seq.), which authorized HUD to establish and enforce construction and safety standards for factory-built manufactured housing.
Congress granted HUD this authority primarily to ease the administrative burden on manufacturers while establishing consumer protections, allowing manufacturers to build to a single construction standard that preempts state and local codes. In addition, federal supervision of building standards for manufactured homes reduced the burden on states that lacked resources to adequately oversee the construction of homes within and out of state. Finally, establishing a uniform code applicable to all states decreased manufacturing costs while ensuring a minimum level of safety, thus reinforcing manufactured housing as a safe and affordable housing option.
Congress made significant statutory changes through the Manufactured Housing Improvement Act (MHIA) of 2000. The changes included granting HUD the authority, for the first time, to establish model installation standards for manufactured homes that would become nationwide minimum standards. These installation standards do not have the same preemptive effect as the construction and safety standards; rather, they establish minimum requirements for manufacturers to address through home installation instructions. The MHIA also created the Manufactured Housing Consensus Committee (MHCC), a federal advisory committee composed of 21 voting members representing manufactured housing producers, retailers, consumers and consumer organizations, and general interest and public officials with an interest in manufactured housing. MHCC is responsible for recommending changes to both the construction and safety code and installation standards.
HUD’s manufactured housing program, implementing the statutory distinctions, differentiates between construction and installation activities. The construction and safety standards, which were authorized by the National Manufactured Housing Construction and Safety Standards Act of 1974, provide requirements that must be met before a home may be shipped from the production facility and generally cover the design and construction of manufactured homes. The 1974 Act established the requirements for manufacturers to self-certify that their manufactured homes conform with the
Federal Manufactured Home Construction and Safety Standards. Such certification is required to be in the form of a
label or tag permanently affixed to each transportable section (floor) of a manufactured home.
HUD’s model installation standards, authorized by the MHIA, provide requirements affecting manufacturers’ installation instructions and the work performed at the site as part of the placement of the home, such as the foundation, anchorage, close-up work, and postplacement connections of some appliances and utility systems.
In 2018, nearly 97,000 homes consisting of approximately 150,000 transportable sections were produced under this national building regulatory program. Approximately 135 manufacturing plants are located across the United States. Manufactured housing represents roughly 10 percent of all new single-family construction starts and constitutes higher percentages in rural areas.