Housing Supply and Affordability Act This bill allows the Department of Housing and Urban Development to award grants to states, local governments, Indian tribes, and Native Hawaiian organizations for the development and implementation of housing policy plans. These plans must increase the housing supply while avoiding resident displacement, increase housing affordability, and reduce barriers to housing development. The bill also provides funding for the grants. The amounts provided by the bill are designated as an emergency requirement for the purposes of the Statutory Pay-As-You-Go (PAYGO) Act of 2010, the Senate PAYGO rule, and other budget enforcement procedures. (This excludes the budget effects from being counted for the purposes of the PAYGO rules and other budget enforcement procedures.)