The Homebuilding Materials Tariff Relief Act exempts critical homebuilding products from tariffs imposed after January 20, 2025, including lumber, plywood, drywall, insulation, glass, stone, ceramic tiles, and numerous other construction materials specified by their tariff classification codes. The President can only reimpose tariffs on these materials if housing affordability becomes severely constrained, measured by the National Association of Realtors Housing Affordability Index reaching 160 or higher, and only if Congress approves the reimposition through an expedited joint resolution process. The bill aims to lower residential construction costs by shielding homebuilding materials from recent tariff increases, while maintaining protections for anti-dumping and trade remedy tariffs.