Substructure refers to a building's Equipment and mechanical systems Framing and insulation Building area above grade Foundation structure The Federal Housing Administration (FHA) Guarantees mortgage loans Insures mortgage loans Makes residential mortgages, collects payments, and forecloses when necessary Is a state agency with far-reaching goals The area of a site measuring 75 by 135 feet is 0.2324 acre 2.324 acres 10,900 square feet 2 hectares (1 hectare =2.471 acres )