Housing Supply Expansion Act This bill modifies the federal prevailing wage rates that apply to federally assisted housing and requires the Department of Labor to review and revise its process for determining prevailing wage rates. Specifically, the bill applies the prevailing wage rate for residential construction to all housing projects that receive assistance under specified federal statutes. (Under current law, the residential construction prevailing wage rate applies to the construction, alteration, or repair of single-family homes or apartment buildings up to four floors in height.)