Hand of a Lock or Door - Indicates the direction of swing or movement and/or locking security side of a door; designated as left hand, left hand reverse, right hand, or right hand reverse. The hand of the door is determined by looking from the “outside”. For example, you view a bedroom door from the hallway and an exterior door from outside the building. When you view the door from the “outside” the standard designation of handedness – right hand-left hand- the door will swing away from you. If the hinges were on the right, this would be a right hand door. If, however, when you view the door from the “outside”, but the door swings towards you this would be a reverse door.

H Clip - Small metal clips formed like an "H" that fits at the joints of two plywood (or wafer board) sheets to stiffen the joint. Normally used on the roof sheeting.

Half-Bath- A bathroom that does not contain a shower or a bathtub. The room simply contains a toilet and a sink.

Hardpan- A compacted layer of soils.

Hardware- All of the "metal" fittings that go into the home when it is near completion. For example, door knobs, towel bars, handrail brackets, closet rods, house numbers, door closers, etc. The interior trim carpenter installs the "hardware".

Haunch- An extension, knee like protrusion of the foundation wall that a concrete porch or patio will rest upon for support.

Hawk- A metal square with a wooden handle at the center, used by a plasterer or tile setter, to temporarily hold mortar or plaster; commonly, a rubber pad fits over the handle and covers that portion of the metal hawk that would come in contact with the hand.

Hazard Insurance - Protection against damage caused by fire, windstorms, or other common hazards. Many lenders require borrowers to carry it in an amount at least equal to the mortgage.

Header- (a) A beam placed perpendicular to joists and to which joists are nailed in framing for a chimney, stairway, or other opening. (b) A wood lintel. (c) The horizontal structural member over an opening (for example over a door or window).

Headroom- Vertical clearance in a passageway or above a stairway, measured from the edge of the nosing.

Hearth- The fireproof area directly in front of a fireplace. The inner or outer floor of a fireplace, usually made of brick, tile, or stone.

Heartwood- Central portion of a tree, which is stronger and more decay-resistant than the surrounding sapwood.

Heat Detector - A fire detector designed to operate at a predetermined temperature or rate of temperature rise.

Heat Exchanger - A structure that transfers heat from one gas or liquid to another gas or liquid. For example, the hot combustion gases in a furnace to the circulating household air or, in a boiler, to the circulating hot water.

Heat Gain - The amount of heat gained, measured in BTU's, from a space to be conditioned, at the local summer outdoor design temperature and a specified indoor design condition.

Heating Degree Day(s) (HDD) - The number of degrees per day that the daily average temperature (the mean of the maximum and minimum recorded temperatures) is below a base temperature, usually 65 degrees Fahrenheit, unless otherwise specified; used to determine indoor space heating requirements and heating system sizing. Total HDD is the cumulative total for the year/heating season. The higher the HDD for a location, the colder the daily average temperature(s).

Heating Load - The amount of heating required to keep a building at a specified temperature during the winter.

Heat Loss - The amount of heat lost, measured in BTU's from a space to be conditioned, at the local winter outdoor design temperature and a specified indoor design condition.

Heat Pump - A mechanical device which uses compression and decompression of gas to heat and/or cool a house.

Heat Recovery Ventilator (HRV) - A device used in central ventilation systems to reduce the amount of heat that is lost as household air is replaced with outside air. As fresh air enters the house, it passes through a heat exchanger heated by the warm outgoing air stream and is preheated.

Heat Register - The grilled opening into a room by which the amount of warm air from a furnace can be directed or controlled; may include a damper.

Heat Rough - Work performed by the heating contractor after the stairs and interior walls are built. This includes installing all duct work and flue pipes. Sometimes, the furnace and fireplaces are installed at this stage of construction.

Heat Trim - Work done by the heating contractor to get the home ready for the municipal Final Heat Inspection. This includes venting the hot water heater, installing all vent grills, registers, air conditioning services, turning on the furnace, installing thermostats, venting ranges and hoods, and all other heat related work.

Hectare- An area equal to 100 meters by 100 meters

Heel Cut - A notch cut in the end of a rafter to permit it to fit flat on a wall and on the top, doubled, exterior wall plate. See: Bird's-mouth cut

HEPA®- An acronym for 'High Efficiency Particulate Air'. HEPA filters originated in the 1940's. A true HEPA® is the best known filter for removing at least 99.97% of particulates such as dust, animal dander, smoke, mold and other allergens that are 0.3 microns or larger, from the air and thus improving air quality.

High-Efficiency Furnace or Boiler - A heating unit with an annual fuel utilization efficiency (AFUE) of 90 per cent or more. It has a second stainless steel heat exchanger that removes additional heat from exhaust gases. Water vapour condenses as the exhaust cools. The unit vents through a narrow plastic wall pipe instead of a chimney.

Highlights- A light spot, area, or streak on a painted surface.

Hinge Jamb - The vertical member of a door frame to which the hinges are applied.

Hinge Stile - The vertical edge of a door where hinges are installed.

Hip- A roof with four sloping sides. The external angle formed by the meeting of two sloping sides of a roof.

Hip Roof - A roof that rises by inclined planes from all four sides of a building.

Hollow Core Door - A non-metal door with structural reinforcement creating air pockets between the two faces.

Hollow Metal Door - Typically a door made of sheet metal on all surfaces and lightly reinforced to make it rigid.

Home Run (Electrical) - The electrical cable that carries power from the main circuit breaker panel to the first electrical box, plug, or switch in the circuit.

Honey Combs - The appearance concrete makes when rocks in the concrete are visible and where there are void areas in the foundation wall, especially around concrete foundation windows.

Hose Bib - An exterior water faucet (sill cock).

Hot Wire - The wire that carries electrical energy to a receptacle or other device—in contrast to a neutral, which carries electricity away again. Normally the black wire. Also see ground

HRAI - The Heating, Refrigeration and Air Conditioning Institute of Canada (HRAI) is the country’s largest industry trade association, representing approximately 1,000 professional contractors, and hundreds of industry manufacturers and distributors.

Humidifier- An appliance normally attached to the furnace, or portable unit device designed to increase the humidity within a room or a house by means of the discharge of water vapor.

Hurricane Clip - Metal straps that are nailed and secure the roof rafters and trusses to the top horizontal wall plate. Sometimes called a Teco clip.

HVAC- An abbreviation for Heat, Ventilation, and Air Conditioning

Hydraulic Shock - The instantaneous pressure caused when a closed plumbing valve stops flowing water.