This bill increases loan limits for property improvement and manufactured housing loans under the National Housing Act and expands what these loans can be used for. Specifically, it raises the maximum loan amount for home alterations and repairs from $60,000 to $150,000, increases limits for manufactured home purchases ranging from roughly $106,000 to $238,000 depending on the home type, and allows property improvement loans to be used for building accessory dwelling units like granny flats or guest homes. The bill also requires the Department of Housing and Urban Development to develop an annual indexing method within one year to automatically adjust these loan limits over time, and directs HUD to study the cost-effectiveness of factory-built housing including manufactured and modular homes. These changes aim to make it easier and more affordable for homeowners to finance improvements and for people to purchase factory-built homes, while also supporting the development of accessory housing units.