Public Buildings Renewal Act of 2021 This bill allows tax-exempt financing of certain government-owned buildings by expanding the definition of exempt facility bond to include bonds used for qualified government buildings. A qualified government building is a government-owned building or facility that consists of one or more of the following an elementary or secondary school; a facility of a state college or university used for educational purposes; a public library; a court; a hospital or health care facility; a laboratory or research facility used by a governmental unit; a public safety facility; or an office for government employees. The bill excludes buildings or facilities that include specified recreational equipment or are used for the primary purpose of providing retail food and beverage services, recreation, or entertainment. The bill establishes (1) a $5 billion limit on the amount of tax-exempt financing which may be provided for government buildings, and (2) procedures for allocating and applying for the financing. The bill exempts the bonds for government buildings from the volume cap on private activity bonds.