Header     A structural member placed above openings such as a doors, windows, or free ends of floor joists, designed to distribute the load from across the opening to studs, rafters or parallel floor joists.
Heat pump    A device which uses compression and decompression of gas to heat and/or cool a house
Hip roof    A type of roof formed by sloping roof planes on all four sides, with no gables.
Hip shingles    Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.
HVAC    A heating, ventilation and air conditioning system that distributes air through ducts or plenum space.