H-clip:A small metal clip in the shape of the letter H that fits at the joint of two plywood or waferboard sheets used to stiffen the joint at roof sheeting.
habitable space:The space in a structure used for living, sleeping, eating and cooking. Bathrooms, closets, hallways, storage areas and utility rooms are not considered habitable spaces.
hardware:Metal accessories, such as hinges, door knobs, drawer pulls, towel bars, toilet paper holders, etc.
hatch:An opening in a deck, floor or roof whose purpose is to provide access from inside the home or building.
haunch:A knee-like protrusion or extension of a foundation wall upon which a concrete porch or patio rests for support.
hawk:A flat wood or metal tool that is 10 inches to 14 inches square and having a handle that is used by workers to carry plaster, mortar or mud. Also called a mortarboard.
hazard insurance:Insurance for a building used to cover losses while it is under construction.
header:The framing members over windows, doors and other openings. A beam placed perpendicular to joists and to which joists are nailed in framing for a chimney, stairway, or other opening. Also called a wood lintel.
hearth:The inner and outer floor of a fireplace, usually made of brick, tile or stone.
hearth extension:The non-combustible material in front of and at the sides of a fireplace opening.
heartwood:The wood extending from the pith to the sapwood, the cells of which no longer participate in the life processes of the tree.
heat meter:A device that measures the temperature at a domestic heat panel and used for estimating the heat energy being consumed by more than two households served by the same central heater. Also called a heat-allocation meter.
heat pump:A device that uses compression and decompression of gas to heat and/or cool a house.
heat rough:The work performed by the heating or HVAC contractor after the stairs and interior walls are built, and includes installing all ductwork and flue pipes. The furnace and fireplace are sometimes installed at this stage of construction.
heat trim:The work performed by the heating or HVAC contractor to prepare a new-construction home for the final municipal heat inspection. This work includes venting the hot water heater and range, and installing all vent grilles, registers, thermostats, vent hoods, air-conditioning services, turning on the furnace, and all other heat-related work.
heat-strengthened glass:Flat or bent glass that has been heat-treated to a specific surface and/or edge-compression range to meet the requirements of ASTM C 1048, Type HS. Heat-strengthened glass is approximately two times as strong as annealed glass of the same thickness when exposed to uniform static pressure loads. Heat-strengthened glass is not considered safety glass and will not completely dice in the manner that fully tempered glass will.
heated slab:Slab-on-grade construction in which the heating elements are placed within or under the slab.
heating load:The amount of heating required to keep a home or building at a specified temperature during the winter (usually, 65° F), regardless of the outside temperature.
heating seasonal-performance factor (HSPF):A measure of a heat pump's energy efficiency over one heating season, representing the total heating output of a heat pump (including supplementary electric heat) during the normal heating season (in BTUs), as compared to the total electricity consumed (in watt-hours) during the same period. HSPF is based on tests performed in accordance with AHRI 210/240 (AHRI 2003).
heel bead:Sealant applied at the base of a channel after setting a glass lite or panel and before installing the removable stop in order to prevent air leakage and moisture intrusion past the stop.
heel cut:A notch cut into the end of a rafter that permits it to fit flat on a wall and on the top doubled exterior wall plate.
hermetic seal:A vacuum seal between the panes of a double-paned window or insulated glass unit (IGU). A hermetic seal that fails causes permanent fogging between the panels of the IGU.
high-early cement:A Portland cement sold as Type III that sets up to its full strength faster than other types. Also called high early-strength cement.
highlight:A light spot, streak or area on a painted surface.
hinge:A jointed or flexible component that allows the turning or pivoting of a part, such as a door or lid, on a stationary frame.
hip:The external angle formed by the meeting of two sloping sides of a roof.
hip rafter:A rafter that forms the intersection of an external angle at a roof.
hip roof:A roof that rises by inclined planes from all four sides of the building.
hip shingles:Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.
hoistway:A shaft used for the travel of one or more elevators.
home inspection:See general home inspection.
home run (electrical):The electrical cable that carries power from the main circuit breaker panel or panelboard to the first electrical box, plug or switch in the circuit.
honeycomb:Areas in a foundation wall where the aggregate (gravel) is visible. Honeycombs can usually be remedied by applying a thin layer of grout or other cement product over the affected area. Also, a method by which concrete is poured and not puddled or vibrated, allowing the edges to have voids or holes after the forms are removed.
hood:A device installed over a range or cooktop that directs and captures grease-laden vapors and gases into an exhaust system, which then are vented to the exterior.
horizontal:Parallel to or in the plane of the horizon.
hose bibb:An outdoor faucet with hose threads on its spout for the attachment of a garden hose, lawn sprinkler device, etc. Also installed at the interior for the attachment of a washing machine, wash basin, utility sink, etc. Hose bibbs, including the “frostproof” types, may freeze. Therefore, they should be equipped with an accessible stop-and-waste-type valve inside the home so they can be drained during cold weather. There's an exception. Frostproof hose bibbs that extend through the exterior wall's insulation into a warm or conditioned space do not need to be separately valved (2021 IRC P2903.10).
hot wire:The typically black wire that carries electrical energy to a receptacle or other device?in contrast to a neutral, which carries electricity away again.
household appliances:Portable or semi-portable appliances, such as refrigerators, microwave ovens, portable dishwashers, clothes washers and dryers, window air-conditioners, and similar items.
hub:In plumbing, the enlarged end of a pipe that is made to provide a connection into which the end of a joining pipe will fit.
humidifier:A device designed to increase the humidity within a room or a house by means of the discharge of water vapor. It may consist of an individual room-size unit or a larger unit connected to the heating plant to condition the entire house.
humidistat:A device used to automatically control relative humidity indoors.
hurricane clips:Metal straps that are nailed to secure the roof rafters and trusses to the top horizontal wall plate in structures that are subject to hurricane winds. Sometimes called TECO clips based on the U.K. brand TECO.
hurricane ties:Metal fasteners that are used to secure rafters in structures that are subject to hurricane winds.
HVAC:Acronym for heating, ventilation and air conditioning; refers to the system, work, and type of contractor.
hydro-electric elevator:An elevator where liquid is pumped under pressure directly into a cylinder by a pump driven by an electric motor without an accumulator between the pump and cylinder.
