This legislation, titled the Housing Supply Expansion Act of 2025, significantly updates the definition of a manufactured home by striking the requirement for it to be built "on a permanent chassis." This change broadens the scope to include homes constructed without a permanent chassis , with the goal of expanding housing supply. The Secretary of Housing and Urban Development is mandated to issue revised standards specifically for these newly defined manufactured homes, which will include requirements for distinct labels, data plates, and invoice notations to differentiate them from homes built on a permanent chassis. A central provision of the Act requires states to submit an initial certification within one year (or two years for states with biennial legislatures) confirming that their laws and regulations treat all manufactured homes, including those without a permanent chassis, in parity. This equal treatment must extend to areas such as financing, titling, insurance, manufacturing, sales, and taxation. States must also provide annual recertifications to ensure ongoing compliance and confirm that any new laws or regulations do not undermine this parity. The bill establishes clear consequences for states that fail to meet these certification requirements. If a state does not submit the necessary initial or annual certifications, it will be prohibited from the manufacture, installation, or sale of "covered manufactured homes" within its jurisdiction. These covered homes are defined as those constructed after the Act's enactment, built without a permanent chassis, and not recognized as manufactured homes under state law despite meeting the federal definition. The Secretary will also offer model guidance to assist states in successfully submitting their certifications.