RESIDENTIAL

HOUSING TERMS
A GLOSSARY

A GLOSSARY OF NORTH AMERICAN HOUSING AND ENERGY EFFICIENCY TERMS

 I TS
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REED GLOSSARY OF HOUSING TERMS

GLOSSARY OF HOUSING TERMS

A
ABOVE GRADE
A term applied to any part of a structure or site feature that is above the adjacent
finished ground level.

ACTIVATED CARBON
A form of carbon made porous by special treatment making it capable of absorbing
various odours and vapours.

ACTIVE SOLAR ENERGY SYSTEM

A system which requires the importation of energy from outside of the immediate
environment: eg, energy to operate fans and pumps.

ADOBE
A sun dried, unburned brick of clay (earth) and straw used in construction. Within the
United States, adobe is used primarily in the Southwest.

AEROSOL
A gaseous suspension of small particles of a liquid or a solid.

AGGREGATE
A coarse material, such as gravel, broken stone or sand, with which cement and
water are mixed to form concrete. Crushed stone is usually designated as coarse
aggregate and sand as fine aggregate.

AIR BARRIER
A material carefully installed within a building envelope assembly to minimize the
uncontrolled passage of air into and out of a dwelling.

AIR CHANGE PER HOUR (ACH)

A unit that denotes the number of times a house exchanges its entire volume of air
with outside air in an hour. This is generally used in two ways: 1) under natural
conditions and 2) under a 50 Pascal pressure difference.

AIR FILM
The layer of air next to a surface, such as a glass pane, which offers some resistance
to heat flow.

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REED GLOSSARY OF HOUSING TERMS

AIR LEAKAGE
The uncontrolled flow of air through a component of the building envelope itself,
when a pressure difference is applied across the component. Infiltration refers to
inward flowing air leakage and exfiltration refers to outward flowing air leakage.

AIR SEALING
The practice of sealing unintentional gaps in the building envelope (from the interior)
in order to reduce uncontrolled air leakage.

AIRWAY
The space left between roof insulation and roof decking to allow free movement of
air.

ALBEDO
The reflectance of solar radiation for a given surface is referred to as the albedo rate.

ALTERATION
Any building change that does not alter the total volume.

ANCHOR BOLTS
The bolts securing a wooden sill plate to a concrete or masonry floor or wall.

ANGLE OF INCIDENCE
The angle that the sun's rays make with a line perpendicular to a surface. The angle
of incidence determines the percentage of direct sunshine intercepted by a surface.

ATTIC OR ROOF SPACE

The space between the top floor ceiling and roof, and between a dwarf partition and
sloping roof.

ATTIC VENTILATORS
The screened openings in houses provided to ventilate an attic space. They are
located in the soffit area as inlet ventilators and in the gable end or along the ridge
as outlet ventilators. They can also consist of power-driven fans used as an exhaust
system. See also LOUVER.

AWNING
A shading device on a metal frame mounted on the outside of the window.

AWNING WINDOW
A top hinged sash.

AZIMUTH
The angular distance between true south and the point on the horizon directly below
the sun.

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REED GLOSSARY OF HOUSING TERMS

B
BACKDRAFTING (FLOW REVERSAL)
The reverse flow of chimney gases into the building through the barometric damper,
draft hood, or burner unit. This can be caused by chimney blockage or it can occur
when the pressure differential is too high for the chimney to draw.

BACK FILL
The material used to re-fill an excavation around the outside of a foundation wall or
pipe trench.

BALLOON FRAMING
A method of wood-frame construction in which the studs extend in one piece from the
foundation sill to the top plate supporting the roof.

BASEBOARD
A molded board placed against the wall around a room next to the floor to conceal
the joint between the floor and wall finish.

BASE COURSE
In masonry, the first or bottom course of brick or other masonry units.

BASEMENT
The lower storey of a building, below or partly below ground level.

BATTEN
A narrow strip of wood used to cover joints between boards or panels.

BATTER BOARD
The boards set at right angles to each other at each corner of an excavation, used
to indicate the level and alignment of the foundation wall.

BAY WINDOW
A window which projects outside the main line of a building.

BEAM
A horizontal structural member, usually wood, steel or concrete, supported at two or
more points but not throughout its length.

BEAM POCKET
A notch formed at the top of a wall to receive and support the end of a beam.

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REED GLOSSARY OF HOUSING TERMS

BEARING
The part of a joist, rafter, truss or beam which actually rests on its support and the
area of the support on which it rests.

BEARING PARTITION
A partition that supports any vertical load in addition to its own weight.

BEARING WALL
A wall that supports any vertical load in addition to its own weight.

BERM
A man-made mound or small hill of earth.

BEVEL
The sloping surface formed when two surfaces meet at an angle which is not a right
angle.

BEVEL SIDING
Any boards tapered to a thin edge and used as exterior wall covering.

BLIND-NAILING
The practice of nailing so that the nailheads are not visible on the face of the work
- usually at the tongue of matched boards.

BLOCKING
The short pieces nailed between major framing members to act as fire-stops or
provide a nailing surface.

BOARD
Any lumber less than nominally 2 inches (51 mm) thick and wider than 4 inches (100
mm).

BOTTOM PLATE
The lower horizontal member of a wood-frame wall nailed to the bottom of the wall
studs and to the floor framing members.

BRACE
A diagonal framing member fastened to major horizontal and vertical members to
provide a triangle and thereby stiffen the framing.

BREAKING JOINTS
The manner of laying masonry units so as to avoid vertical joints in adjacent courses
from lining up. Also the distribution of joints in boards, flooring, lath and panels so no
two adjacent end-joints are directly in line.

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REED GLOSSARY OF HOUSING TERMS

BRICK MOLDING
A standard milled wood trim piece to cover the gap between the window frame and
masonry.

BRICK VENEER
A facing of brick tied to a wood frame or masonry wall, serving as a wall covering
only and carrying no structural loads.

BTU
An abbreviation for British Thermal Unit; the heat required to increase the
temperature of one pound of water one degree Fahrenheit.

BUILT-UP ROOF
A roof covering composed of three or more layers of roofing felt or fibreglass
saturated with coal, tar or asphalt. The top is finished with crushed stone, gravel or
a cap sheet. Generally used on flat or low-pitched roofs.

BUTT-JOINT
Any joint made by fastening two members together without overlapping.

C
CANT STRIP
A triangular-shaped piece of lumber used around the perimeter of flat roofs or at the
junction of a flat deck and a wall to prevent cracking of the roofing which is applied
over it.

CASEMENT WINDOW
A frame which contains a sash hinged at the side to open in or out. In-swinging are
French in origin while out-swinging are from England.

CASING
A form of molded trim used around window and door openings.

CAULKING
The practice of sealing a joint in a building.

CENTRE-HUNG SASH
A sash that pivots on pins in the middle of the sash stiles and sides of the window
frame to allow access for cleaning from the inside.

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REED GLOSSARY OF HOUSING TERMS

CHECKING
The fissures that appear with age in many exterior paint coatings, at first superficial,
but which in time may penetrate entirely through the coating. They may also appear
in siding or lumber.

CHIMNEY FLUE
A passage housed in a chimney through which smoke and gases are carried from a
fuel burning appliance, fireplace or incinerator to the exterior.

CLERESTORY
An outside wall of a room or building, carried above an adjoining roof and pierced
with windows.

COLLAR BRACE (COLLAR TIE)

A horizontal piece of lumber used to provide intermediate support for opposite roof
rafters, usually located in the middle third of the rafters. Also called collar beam or
collar tie.

COLUMN
A vertical free-standing load-carrying member.

COMBINATION DOORS OR WINDOWS

The combination doors or windows used over regular openings. They provide winter
insulation and summer protection and often have self-storing or removable glass and
screen inserts. This eliminates the need for handling a different unit each season.

COMBUSTIBLE AND NON-COMBUSTIBLE MATERIALS

Within the range of temperatures that may occur in a building either normally or under
fire conditions, materials are classified as combustible or non-combustible. The term
non-combustible is generally applied to materials of construction which conform to
National Standard of Canada. CAN4S114-78, Standard Method of Test for
Determination of Non-Combustibility in Building Materials. Scarborough, Ontario:
Underwriters Laboratories of Canada, 1980.

COMBUSTION AIR
The air required to provide adequate oxygen for fuel burning appliances in the
building. The term 'combustion air' is often used to refer to the total air requirements
of a fuel burning appliance including both air to support the combustion process and
air to provide chimney draft (dilution air).

COMMON RAFTER
One of a series of rafters extending from the top of an exterior wall to the ridge of a
roof.

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REED GLOSSARY OF HOUSING TERMS

CONDENSATION
The transformation of the vapour content of the air into water on cold surfaces. The
beads or drops of water (and frequently frost in extremely cold weather) that
accumulate on the inside of the exterior covering of a building when warm,
moisture-laden air from the interior reaches a point where the temperature no longer
permits the air to sustain the moisture it holds.

CONDUCTION
The transfer or travel of heat through a body by molecular action.

CONDUIT (ELECTRICAL)
A pipe, usually metal, in which wire is installed.

CONSTRUCTION DRY-WALL
A type of construction in which the interior wall finish is applied in a dry condition,
generally in the form of sheet materials or wood panelling, as opposed to plaster.

CONSTRUCTION, WOOD FRAME

A type of construction in which the structural parts are wood or depend upon a wood
frame for support. In codes, if masonry veneer is applied to the exterior walls, the
classification of this type of construction is usually unchanged.

CONVECTION
The transfer of heat by the movement of a fluid (water, air, etc.).

CONVECTIVE LOOPS
A type of air movement occurring in and around the building envelope caused by
gaps in the insulation, weather barrier or air barrier. For example, in an uninsulated
wall cavity, air removes heat from the warm interior wall, then circulates to the colder
exterior wall where it loses the heat.

CORBEL OUT
The practice of building out one or more courses of brick or stone from the face of a
wall, often used to form a support for timbers.

CORNER BOARDS
A built-up wood member installed vertically on the external corners of a house or
other frame structure against which the ends of the siding are butted.

CORNER BRACES
The diagonal braces at the corners of a frame structure used to stiffen and strengthen
the wall.

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REED GLOSSARY OF HOUSING TERMS

CORNICE
A horizontal projection at the top of a wall or column; often referring to the overhang
of a pitched roof at the eave line, usually consisting of a facia board, a soffit or a
closed cornice and appropriate moldings.

COUNTERFLASHING
A flashing usually used on chimneys at the roofline to cover shingle flashing and to
prevent moisture entry.

COURSE
A continuous horizontal layer of bricks or masonry units in buildings; the term is also
applicable to shingles.

COVE MOLDING
A molding with a concave face used as a trim or to finish interior corners.

CRAWL SPACE
A shallow space below the living quarters of a basementless house, normally
enclosed by the foundation wall.

CROSS-BRIDGING
The diagonal bracing between adjacent floor joists, placed near the centre of the joist
span to prevent joists from twisting.

CURING (OF CONCRETE)

The maintenance of proper temperature and moisture conditions to promote the
continued chemical reaction which takes place between the water and the cement.

CUT-IN BRACE
A nominal 2 inch (51 mm) thick member, usually a 2 x 4 (38 mm by 89 mm) cut in
between each stud diagonally.

D
DAMP-PROOF COURSE
A damp-proof material placed just above the ground level in a brick or stone wall to
prevent ground moisture from seeping up through the structure.

DAMP-PROOFING
The process of coating the outside of a foundation wall with a special preparation to
resist passage of moisture through the wall. Material used to resist the passage of
moisture through concrete floor slabs and from masonry to wood.

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REED GLOSSARY OF HOUSING TERMS

DEAD AIR SPACE (STILL AIR SPACE)

A confined space of air. A dead air space tends to reduce both conduction and
convection of heat. This fact is utilized in virtually all insulation materials and
systems, such as double glazing, fibreglass batts, rigid foam panels and loose fill
insulations, such as vermiculite and cellulose.

DECAY
The disintegration of wood or other substance through the action of fungi.

DEGREE DAY (HEATING)

The difference between a base temperature and the average temperature of a day.
The base is usually 18°C (64°F).

DENSITY
The mass of a substance in a unit volume. When expressed in the metric system, it
is numerically equal to the specific gravity of the same substance.

DEWPOINT
The temperature at which a vapour begins to deposit as a liquid. Applies especially
to water in the atmosphere.

DIFFUSE RADIATION
Radiation that has travelled an indirect path from the sun because it has been
scattered by particles in the atmosphere, such as air molecules, dust and water
vapour.

DIFFUSION
The movement of water vapour between 2 areas caused by a difference in vapour
pressure, independent of air movement. The rate of diffusion is determined by 1) the
difference in vapour pressure, 2) the distance the vapour must travel, and 3) the
permeability of the material to water vapour. Hence the selection of materials of low
permeability for use as vapour retarders in buildings.

DILUTION AIR
The air required by some combustion heating systems in order to isolate the furnace
from outside pressure fluctuations and to maintain an effectively constant chimney
draft.

DIRECT GAIN
Solar energy collected (as heat) in a building without special solar collection devices,
such as through windows or by being absorbed by a roof or exterior walls.

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REED GLOSSARY OF HOUSING TERMS

DIRECT NAILING
The practice of nailing perpendicular to the initial surface or to the junction of the
pieces joined. Also termed face nailing. Fastening a member by driving nails through
it at right angles to its exposed surface.

DOOR JAMB
The surrounding case into and out of which a door closes and opens. It consists of
two upright pieces, called side jambs, and a horizontal head jamb.

DORMER
An opening in a sloping roof, the framing of which projects out to form a vertical wall
suitable for windows or other openings.

DOUBLE-HUNG WINDOW
Window with two vertically moving sashes, each closing a different part of the
window.

DOUBLE GLAZING
Two panes of glass in a door or window, with an air space between the panes. They
may be sealed hermetically as a single unit or each pane may be installed separately
in the door or window sash.

DOWNSPOUT
A pipe, usually of metal or plastic, for carrying rainwater from roof gutters.

DRESSED AND MATCHED (TONGUE AND GROOVE)

A board or plank machined in such a manner that there is a groove on one edge and
a corresponding tongue on the other.

DRIP CAP
A molding placed on the exterior top side of a door or window frame to cause water
to drip beyond the outside of the frame or at the bottom of a wall of siding (drip mold).

DRUM WALL
A type of wall using stacked 55 gallon drums for heat storage.

DRY ROT
A fungus that decays wood in the presence of moisture and warm conditions and in
the absence of light.

DRYWALL FINISH
The interior wall and ceiling finish other than plaster - e.g. gypsum board, plywood,
fiberboard panels, etc.

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REED GLOSSARY OF HOUSING TERMS

DUCTS
The round or rectangular metal pipes in a house used for distributing warm air from
the heating plant to rooms, or air from a conditioning device or as cold air returns.

DWARF WALL
A framed wall of less than normal full height. (Also called a knee-wall).

E
EAVE
The lower part of a roof which projects beyond the face of the walls.

EAVE SOFFIT
The under surface of the eave.

EAVE TROUGH
A trough fixed to an eave to collect and carry away the run-off from the roof. Also
called a gutter.

END MATCHED
A board having tongued and grooved ends.

EQUIVALENT LEAKAGE AREA (ELA)

The total area of all the unintentional openings in a building's envelope, generally
expressed in square centimetres.

EXFILTRATION
The uncontrolled leakage of air out of a building.

EXPANDED METAL
A metal network formed by stamping or cutting sheet-metal and stretching it to form
open meshes. It is used as reinforcing in concrete construction and as lath for
plastering and stucco.

F
FACE NAILING
The practice of fastening a member by driving nails through it at right angles to its
exposed surface.

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REED GLOSSARY OF HOUSING TERMS

FAN
An air moving device comprising a wheel or blade, and housing or office plate.

FASCIA BOARD
A finish member around the face of eaves and roof projections.

FENESTRATION
The area and arrangement of windows.

FIRE-RESISTANCE RATING
The time in hours or fraction thereof that a material or assembly of materials will
withstand the passage of flame and the transmission of heat when exposed to fire
under specified conditions of test and performance criteria.

FIRE-RESISTIVE
A designation applied, in the absence of a specific ruling by the authority having
jurisdiction, to materials for construction not combustible in the temperatures of
ordinary fires; materials that will withstand such fires without serious impairment of
their usefulness for at least 1 hour.

FIRE-RETARDANT CHEMICAL
A chemical or preparation of chemicals used to reduce flammability or to retard
spread of flame.

FIRE STOP
A solid, tight closure of a concealed space, placed to prevent the spread of fire and
smoke through such a space. In a frame wall, this will usually consist of 2 x 4 (38 mm
by 89 mm) cross blocking between studs.

FISHPLATE
A wood or plywood piece used to fasten the ends of two members together at a butt
joint with nails or bolts. Sometimes used at the junction of opposite rafters near the
ridge line.

FLASHING
A material, such as sheet metal, used in roof and wall construction to shed water.

FLOORING
A material used in the construction of floors. The surface material is known as finish
flooring while the base material is called subflooring.

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REED GLOSSARY OF HOUSING TERMS

FLUE
The space or passage in a chimney through which smoke, gas, or fumes ascend.
Each passage is called a flue, which together with any others and the surrounding
masonry make up the chimney.

FLUE LINING
A fire clay or terra-cotta pipe, round or square, usually made in all ordinary flue sizes
and in 24 inch (610 mm) lengths, used for the inner lining of chimneys with the brick
or masonry work around the outside. Flue lining in chimneys runs from about 12
inches (305 mm) below the flue connection to the top of the chimney.

FLY RAFTERS
The end rafters of the gable overhang supported by roof sheathing and lookouts.

FOOTCANDLE
Unit of measure of the intensity of light, defined by the light at a distance of one foot
form an International candle.

FOOTING
A masonry section usually concrete, in a rectangular form wider than the bottom of
the foundation wall or pier it supports.

FOUNDATION
The supporting portion of a structure below the first-floor construction, or below
grade, including the footings, which transfers the weight of, and loads of, the
structure to the ground.

FRAMING
The skeleton of the building. The rough timber work of a house, including the flooring,
roofing, partitioning and beams.

FRAMING, BALLOON
A system of framing a building in which all vertical structural elements of the bearing
walls and partitions consist of single pieces extending from the top of the foundation
sill plate to the roofplate and to which all floor joists are fastened.

FRAMING, PLATFORM
A system of framing a building in which floor joists of each storey rest on the top
plates of the storey below or on the foundation sill for the first storey and the bearing
walls and partitions rest on the subfloor of each storey.

FRIEZE
A horizontal member used in house construction to connect the top of the siding with
the soffit of the cornice.

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REED GLOSSARY OF HOUSING TERMS

FROSTLINE
The depth of frost penetration in soil. This depth varies in different parts of the
country. Footings should be placed below this depth to prevent movement.

FUNGI WOOD
The microscopic plants that live in dampwood and cause mold, stain, and decay.

FUNGICIDE
A chemical that is poisonous to fungi.

FURRING
The strips of wood or metal applied to a wall or other surface to even it and normally
to serve as a fastening base for finish material.

G
GABLE
The upper triangular-shaped portion of the end wall of a house above the eave line
of a double sloped roof.

GABLE END
The entire end wall of a house having a gable roof.

GAUGE
A standard for measuring e.g. diameter of nails or wire and thickness of metal sheets,
etc.

GEOTHERMAL ENERGY
Heat energy contained in large underground reservoirs of steam and hot water,
produced by molten material from the earth's interior.

GIRDER
A large beam supporting floor joists at the same level as the sills. A larger or principal
beam used to support concentrated loads at isolated points along its length.

GIRT
A large horizontal beam supporting the ends of upper storey floor joists between
posts.

GLASS
An elastic transparent material composed of silica (sand), soda (sodium carbonate)
and lime (calcium carbonate) with small quantities of alumina, boric or magnesia
oxides.

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REED GLOSSARY OF HOUSING TERMS

GLAZIER'S POINT
A thin metal triangle with one point pounded into the frame to hold the glass, putty is
then applied to seal the glass.

GLOSS (PAINT OR ENAMEL)

A paint or enamel that contains a relatively low proportion of pigment and dries to a
sheen or luster.

GRADE
The surface slope. The level of the ground surface around the foundation wall. To
modify the ground surface by cut and fill.

GRADE LINE
A pre-determined line indicating the proposed elevation of the ground surface around
a building.

GRADE (LUMBER)
A classification of lumber depending upon its suitability for different uses.

GRAIN
The direction, size, arrangement, appearance, or quality of the fibers in wood.

GUSSET
A flat wood, plywood, or similar type member used to provide a connection at
intersection of wood members. Most commonly used at joints of wood trusses. They
are fastened by nails, screws, bolts, or adhesives.

GUTTER OR EAVE TROUGH

A shallow channel or conduit of metal, plastic or wood set below and along the eaves
of a house to catch and carry off rainwater from the roof.

GYPSUM PLASTER
The combination of gypsum with sand and water for making base-coat plaster.

H
HEADER (FRAMING)
A wood member at right angles to a series of joists or rafters at which the joists or
rafters terminate. When used at openings in the floor or roof system the header
supports the joist or rafters and acts as a beam.

HEARTH
The inner or outer floor of a fireplace, usually made of brick, tile, or stone.

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HEAT EXCHANGER
A device specifically designed to transfer heat between two physically separated
fluids, such as air.

HEAT GAIN
An increase in the amount of heat contained in a space, resulting from direct solar
radiation and the heat given off by people, lights, equipment, machinery and other
sources.

HEATING
Air-Conditioning : The process of bringing air to a required state of temperature and
humidity, and removing dust, pollen and other foreign matter.
Baseboard Heater : A radiator shaped like a decorative baseboard having openings
at the top and bottom through which air circulates.
Central Heating : A heating system in which a number of rooms or spaces are
heated from a central source.
Convector : A heating device in which the air enters through an opening near the
floor, is heated as it passes through the heating element and enters the room through
an upper opening.
Hot Water Heating : The circulation of hot water through a system of pipes and
radiators either by gravity or a circulating pump.
Panel Heating : Coils or ducts installed in wall, floor or ceiling panels to provide a
large surface supply of low intensity heat.
Radiant Heating : A heating system in which only the heat radiated from panels is
effective in providing the heating requirements.
Warm Air Heating : A warm air heating plant consisting of a heating unit
(fuel-burning furnace) enclosed in a casing, from which the heated air is distributed
to various rooms of the building through ducts.

HEAT LOSS
A decrease in the amount of heat contained in a space, resulting from heat flow
through walls, windows, roof and other building envelope components.

HEAT PUMP
A heating device which extracts usable heat from a medium like air or water by
raising (pumping) its temperature. In its reverse it can be used for cooling.

HEAT SINK
A body which is capable of accepting and storing heat, and therefore may be used
as a heat source.

HERMETICAL SEALING
The practice of making a material impervious to air and other fluids by fusion.

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HIP
The sloping ridge of a roof formed by two intersecting roof slopes.

HIP-RAFTER
The rafter which forms the hip of a roof.

HIP ROOF
A roof that rises by inclined planes from all four sides of a building.

HOPPER LIGHT
Inward opening sash hinged at the bottom.

HUMIDIFIER
A device designed to increase the humidity within a room or a house by means of the
discharge of water vapour. It may consist of an individual room-size unit or a larger
unit attached to the heating plant to condition the entire house.

HUMIDITY
The amount of water vapour in the air.

I
I-BEAM
A steel beam with a cross section resembling the letter I. It is used for long spans as
basement beams or over wide wall openings, such as a double garage door, when
wall and roof loads are imposed on the opening.

IMPERMEABLE
Not permitting water vapour or other fluid to pass through.

INFILTRATION
The uncontrolled leakage of air into a building.

INSOLATION INCIDENT SOLAR RADIATION

The total amount of solar radiation (direct, diffused and reflected) striking a surface
exposed to the sky. This incident solar radiation is measured in langleys per minute,
or BTU's per square foot per hour or per day.

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INSULATION
Any material high in resistance to heat transmission that, when placed in the walls,
ceiling, or floors of a structure, will reduce the rate of heat flow.
Blown : Low density, loose insulation material which is mechanically installed.
Electrical : Non-conducting covering applied to wire or equipment to prevent short
circuiting.
Friction Fit Batt : Batt insulation which is held secure within framing members by
friction.
Rigid : Dense insulation material that is structurally rigid. Also called board insulation.

INTERIOR FINISH
The covering used on interior walls and ceilings.

INTERIOR TRIM
All the interior woodwork designed to conceal joints.

ISOLATED GAIN SYSTEM

A system where solar collection and heat storage are isolated from the living space.

J
JACK RAFTER
A rafter that spans the distance from the wall-plate to a hip, or from a valley rafter to
the roof ridge.

JAMB
The side post or lining of a doorway, window or other opening.

JOIST
One of a series of horizontal wood members, usually 2 inches (50 mm) nominal
thickness, used for support. (eg floor joist, ceiling joist or roof joist.) A parallel beam
used to support floor and ceiling loads, and supported in turn by larger beams,
girders, or bearing walls.

JOIST HANGER
A steel section shaped like a stirrup, bent so it can be fastened to a beam to provide
end support for joists, headers, etc.

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REED GLOSSARY OF HOUSING TERMS

K
KNEEWALL
Partitions of varying length used to support roof rafters when the span is so great that
additional support is required to stiffen them.

L
LANDING
A platform between flights of stairs or at the termination of a flight of stairs.

LATH
A building material of wood, metal, gypsum or insulating board that is fastened to the
frame of a building to act as a plaster base.

LATITUDE
The angular distance north (+) or south (-) of the equator, measured in degrees of an
arc.

LATTICE
A framework of crossed wood or metal strips.

LEDGER STRIP
A strip of lumber fastened along the bottom of the side of a beam on which joists rest.

LEEWARD
The side (or sides) of a house which face away from the prevailing winds.

LET-IN BRACE
A nominal 1 inch (25 mm) thick board applied into notched studs diagonally.

LIGHT (LITE)
A space in a window sash for a single pane of glass. Also, a pane of glass.

LINEAR FOOT
A length of 12 inches (305 mm) independent of area or volume.

LINTEL
A horizontal structural member that supports the load over an opening such as a door
or window.

19
REED GLOSSARY OF HOUSING TERMS

LIVE LOAD
The weight due to occupancy of a building.

LOOKOUT RAFTERS
The short wood members cantilevered over a wall to support an overhanging portion
of a roof.

LOUVER
An opening with a series of horizontal slats so arranged as to permit ventilation but
to exclude rain, sunlight, or vision. See also ATTIC VENTILATORS.

LUMBER
Any wood which has been sawed and planed only.

LUMBER, BOARDS
Sawn lumber less than 2 inches (51 mm) thick and 4 inches (100 mm) or more wide.

LUMBER, DIMENSION
All yard lumber from 2 inches (51 mm) to, but not including, 5 inches (127 mm) thick
and 2 inches (51 mm) or more wide. Includes joists, rafters, studs, planks, and small
timbers.

LUMBER, DRESSED SIZE

The dimension of lumber after shrinking from green dimension and after machining
to size or pattern.

LUMBER, MATCHED
Any lumber that is dressed and shaped on one edge in a grooved pattern and on the
other in a tongued pattern.

LUMBER, SHIPLAP
Any lumber that is edge-dressed to make a close rabbeted or lapped joint.

LUMBER, TIMBERS
Any yard lumber 5 inches (127 mm) or more in least dimension. Includes beams,
stringers, posts, caps, sills, girders, and purling.

LUMBER, YARD
All lumber of those grades, sizes and patterns which are generally intended for
ordinary construction, such as framework and rough coverage of houses.

LUMEN
A unit of measure for the flow of light, equal to the amount of flow through a unit solid
angle from a uniform point source of one International candle.

20
REED GLOSSARY OF HOUSING TERMS

M
MANSARD ROOF
A double-pitched roof with the lower section containing dormers.

MANTEL
The shelf above a fireplace. Also used in referring to the decorative trim around a
fireplace opening.

MASONRY
The combination of stone, brick, concrete, hollow-tile, concrete-block, gypsum block
or other similar building units or materials, bonded together with mortar to form a wall,
pier, buttress or similar mass.

MASTIC
A pasty material used as a cement (as for setting tile) or a protective coating (as for
thermal insulation, sealing or waterproofing).

MESH
A reinforcement for concrete, plaster or stucco, usually expanded metal or woven
wire.

METAL LATH
A base for plaster or stucco, usually expanded metal or woven wire.

MIL
One-thousandth of an inch, or 0.0254 millimetres.

MILLWORK
All building materials made of finished wood and manufactured in millwork plants and
planing mills are included under the term 'millwork'. It includes such items as inside
and outside doors, window and door frames, blinds, porchwork, mantels, panelwork,
stairways, moldings and interior trim. It normally does not include flooring, ceiling or
siding.

MINERAL WOOL
A material used for insulating buildings, produced by sending a blast of steam
through molten slag or rock; common types now in use include rock wool, glass wool
and slag wool.

MITER JOINT
The joint of two pieces at an angle that bisects the joining angle. For example, the
miter joint at the side and head casing at a door opening is made at a 45° angle.

21
REED GLOSSARY OF HOUSING TERMS

MOISTURE CONTENT OF WOOD

The weight of the water contained in wood, usually expressed as a percentage of the
weight of the oven-dry wood.

MOLDING
A piece of shaped wood used to decorate or conceal a joint.

MORTAR
A substance produced from prescribed proportions of cementing agents, aggregates
and water which gradually sets hard after mixing.

MORTAR BED
The layer of mortar on which any structural member, masonry unit or tile is bedded.

MORTISE
A slot cut into a board, plank, or timber, usually edgewise, to receive a tenon or
another board, plank or timber to form a joint or to receive a lock, hinge, etc.

MUDSILL
Any timber placed directly on the ground as a foundation for a structure.

MULLION
Vertical member between window units.

MUNTIN
A secondary framing member (horizontal, vertical or slanted) to hold the window
panes in the sash. This term is often confused with Mullion.

N
NOMINAL SIZE
The rough size of a member before planing. The ordinary commercial size by which
timber or lumber is known and sold on the market, but it may differ from the actual
size.

NON-BEARING PARTITION
A wall which separates space into rooms, but supports no vertical load except its
own weight.

NON-BEARING WALL
A wall supporting no load other than its own weight.

22
REED GLOSSARY OF HOUSING TERMS

NOTCH
A crosswise rabbet at the end of a board.

O
O.C., ON CENTRE
The measurement of spacing for structural members like studs, rafters and joists in
a building, from the centre of one member to the centre of the next.

OUTRIGGER
An extension of a rafter beyond the wall line. Usually a smaller member nailed to a
larger rafter to form a cornice or roof overhang.

P
PAINT
A combination of pigments with suitable thinners or oils to provide decorative and
protective coatings.

PANE
A sheet of glass for glazing a window. After installation, the pane is referred to as a
'light' (lite) or 'window light'.

PANEL
A large board or sheet of lumber, plywood, or other material. A thin board with all its
edges inserted in a groove of a surrounding frame of thick material. A portion of a flat
surface recessed or sunk below the surrounding area, distinctly set off by molding or
some other decorative device. Also, a section of floor, wall, ceiling or roof, usually
prefabricated and of large size, handled as a single unit in the operations of
assembly and erection.

PAPER, BUILDING
A breather-type sheathing paper usually applied underneath or behind exterior finish
material in wood frame construction. A general term for papers, felts and similar
sheet materials used in buildings without reference to their properties or uses.

PAPER, SHEATHING
A breather type tar or asphalt used under extension wall cladding as protection
against the passage of air or water. A building material, generally paper or felt, used
in wall and roof construction as a protection against the passage of air and
sometimes moisture.

23
REED GLOSSARY OF HOUSING TERMS

PARAPET WALL
The part of an exterior, party or firewall extending above the roof line; a wall which
serves as a guard at the edge of a balcony or roof.

PARGING
A coat of plaster or cement mortar applied to masonry or concrete walls.

PARTITION
A wall that subdivides spaces within any storey of a building.

PERM
An imperial unit measure of water vapour movement through a material (grains per
square foot per hour per inch of mercury difference in vapour pressure.)

PERMEABILITY
A measure of the ease with which water vapour passes through a unit thickness of
a material.

PERMEANCE
Water vapour permeance is the rate of water vapour diffusion through a sheet of any
thickness of material (or assembly between parallel surfaces). It is the ratio of water
vapour flow to the differences of the vapour pressures on the opposite surfaces.
Permeance is measured in perms (m².C/W).

PIER
A column of masonry, usually rectangular in horizontal cross section, used to support
other structural members.

PITCH
The incline slope of a roof or the ratio of the total rise to the total width of a house, i.e.
an 8 feet (2.4 m) rise and 24 feet (7.3 m) width is a one-third pitch roof.

PITCHED ROOF
A roof which has one or more surfaces sloping at angles greater than necessary for
drainage.

PLAIN CONCRETE
Any unreinforced concrete.

PLAN
A drawing representing the horizontal arrangement of a site or building to a given
scale.

24
REED GLOSSARY OF HOUSING TERMS

PLATE
The sill plate : a horizontal member anchored to a masonry wall.
Sole plate : bottom horizontal member of a frame wall.
Top plate : top horizontal member of a frame wall supporting ceiling joists, rafters or
other members.

PLATFORM FRAME
A house frame in which the floor joists of one storey rest on the top plate of the wall
below.

PLUMB
The state of being exactly perpendicular, vertical.

PLY
A term to denote the number of thicknesses or layers of roofing felt, veneer in
plywood, or layers in built-up materials, in any finished piece of such material.

PLYWOOD
A piece of wood made of three or more layers of veneer joined with glue, and usually
laid with the grain of adjoining plies at right angles. Almost always an odd number of
plies are used to provide balanced construction.

POSITIVE PRESSURE
A pressure above atmospheric. In residential construction this refers to pressure
inside the house envelope that is greater than the outside pressure; a positive
pressure difference will encourage exfiltration.

POST
The vertical wall members at the corners and wall intersections.

PRESERVATIVE
Any substance that, for a reasonable length of time, will prevent the action of wood
destroying fungi, borers of various kinds, and similar destructive agents when the
wood has been properly coated or impregnated with it.

PRESSURE DIFFERENCE
The difference in pressure of the volume of air enclosed by the house envelope and
the air surrounding the envelope.

PRIMER
The first coat of paint in a paint job that consists of two or more coats; also the paint
used for such a firstcoat.

25
REED GLOSSARY OF HOUSING TERMS

PURLIN
The members at right angles to rafters serving to break up the roofboard span.

PUTTY
A type of cement usually made of whiting and boiled linseed oil, beaten or kneaded
to the consistency of dough, and used in sealing glass in sash, filling small holes and
crevices in wood, and for similar purposes.

Q
QUARTER ROUND
A molding that has the cross section of a quarter circle.

R
RABBET
A groove cut in the surface along the edge of a board, plank, or other timber.

RADIANT HEATING
A method of heating, usually consisting of a forced hot water system with pipes
placed in the floor, wall or ceiling; or with electrically heated cables or panels.

RADIANT HEAT TRANSFER

The transfer of heat energy from a location of higher temperature to a location of
lower temperature by means of electromagnetic radiation.

RADIATION, ULTRA-VIOLET (UV)

Electromagnetic radiation, usually from the sun, that consists of wavelengths shorter
than the violet end of the visible spectrum (less than 0.15 microns). Five percent of
the sun's radiation is emitted in the ultra-violet band.

RAFTER
A structural member of a roof designed to support roof loads. The rafters of a flat roof
are sometimes called roof joists.

RAFTER, HIP
A rafter that forms the intersection of an external roof angle.

RAFTER, VALLEY
A rafter that forms the intersection of an internal roof angle. The valley rafter is
normally made of double 2 inch (51 mm) thick members.

26
REED GLOSSARY OF HOUSING TERMS

RAKE
The trim members that run parallel to the roof slope and form the finish between the
wall and a gable roof extension.

RECEPTACLE (ELECTRIC)
A mounted electrical outlet.

RECOVERED ENERGY
Energy utilized which would otherwise be wasted.

RECYCLE
Recovery and reuse of materials and resources.

REINFORCING
The practice of placing steel rods or metal fabric in concrete slabs, beams or
columns to increase their strength.

RELATIVE HUMIDITY
The ratio of actual pressure of existing water vapour to maximum possible pressure
of water vapour in the atmosphere at the same temperature, expressed as a
percentage. For example, air containing one half the amount of moisture it is capable
of holding has a relative humidity of 50%.

RESISTANCE VALUE (RSI or R-VALUE)

Thermal resistance value. A metric measurement of the ability of a material to resist
heat transfer.

RIBBON (GIRT)
A 1 inch (25 mm) by 4 inch (102 mm) let into the studs horizontally to support ceiling
or second-floor joists. Replaces the girt in balloon frame.

RIDGE
The horizontal line at the junction of the top edges of two sloping roof surfaces.

RIDGE BEAM
A horizontal structural member usually 2 inches (51 mm) thick, supporting the upper
ends of rafters.

RIDGE BOARD
The board placed on edge at the ridge of the roof into which the upper ends of the
rafters are fastened.

27
REED GLOSSARY OF HOUSING TERMS

ROCK STORAGE SYSTEM

A solar energy system in which the collected heat is stored in a rock bin for later use.
This type of storage can be used in an active, hybrid or even passive system.
However, rock storage is primarily used with a system which circulates air as the
transfer medium between the collector and storage to the heated space.

ROLL ROOFING
A roofing material, composed of fiber and saturated with asphalt, that is supplied in
36 inch (914 mm) wide rolls with a 100 square feet (10 square metres) of material.
Weights are generally 50 to 90 lbs (20 to 41 kg) per roll.

ROOF SHEATHING
The boards or sheet material fastened to the roof rafters on which the shingle or other
roof covering is laid.

ROOFERS
The roofboards nailed to rafters or purling.

ROUGH LUMBER
Any lumber that has been sawn but not planed.

RUBBER-EMULSION PAINT
Any paint, the vehicle of which consists of rubber or synthetic rubber dispersed in
fine droplets in water.

S
SADDLE
The two sloping surfaces meeting in a horizontal ridge, used between the back side
of a chimney, or other vertical surface, and a sloping roof. Also called a cricket.

SASH
The framework which holds the glass in a window.

SASH BALANCE
A device, usually operated by a spring or tensioned weatherstripping designed to
counterbalance double-hung window sash.

SATURATED FELT
A felt which is impregnated with tar or asphalt.

SECTION
A drawing of a building in the vertical plane.

28
REED GLOSSARY OF HOUSING TERMS

SEMIGLOSS PAINT OR ENAMEL

A paint or enamel made with a slight insufficiency of non-volatile vehicle so that its
coating, when dry, has some luster but is not very glossy.

SENSIBLE HEAT
Heat that results in a temperature change.

SHAKE
A shingle split (not sawn) from a block of wood and used for roofing and siding.

SHEATHING
The material covering the house frame on the exterior.

SHEATHING PAPER
See PAPER, SHEATHING.

SHED ROOF
A sloping roof having its surface in one plane.

SHEET METAL WORK

All components of a house employing sheet metal, such as flashing, gutters and
downspouts.

SHEETING
Any material applied in large sheets, usually polyethylene.

SHELLAC
A transparent coating made by dissolving lac, a resinous secretion of the lac bug (an
insect that thrives in tropical countries, especially India), in alcohol.

SHINGLES
Any roof covering of asphalt, asbestos, wood, tile, slate or other material cut to stock
lengths, widths, and thicknesses.

SHINGLES, SIDING
The various kinds of shingles, such as wood shingles or shakes and non-wood
shingles, that are used over sheathing for exterior side wall covering of a structure.

SHIPLAP
See LUMBER, SHIPLAP.

29
REED GLOSSARY OF HOUSING TERMS

SHUTTER
The common lightweight louvered or flush wood or non-wood frames in the form of
doors located at each side of a window. Some are made to close over the window for
protection; others are fastened to the wall as a decorative device.

SIDE LIGHT (MARGIN LIGHT)

A fixed often narrow glass window next to a door opening (or window).

SIDING
The finish covering of the outside wall of a frame building, whether made of horizontal
weatherboards, vertical boards with battens, shingles, or other material.

SIDING, BEVEL (LAP SIDING)

The wedge-shaped boards used as horizontal siding in a lapped pattern. This siding
varies in butt thickness from 1/2 inch (13 mm) to 3/4 inch (19 mm) and in widths up
to 12 inches (305 mm). Normally used over some type of sheathing.

SIDING, DOLLY VARDEN

A bevelled wood siding which is rabbeted on the bottom edge.

SIDING DROP
A siding, usually 3/4 inch (19 mm) thick and 6 inches (152 mm) or 8 inches (203 mm)
wide with tongued-and-grooved or shiplap edges. Often used as siding without
sheathing in secondary buildings.

SILL
The lowest member of the frame of a structure, resting on the foundation and
supporting the floor joists or the uprights of the wall. The member forming the lower
side of an opening, as a door sill, window sill, etc.

SILL PLATE
A structural member anchored to the top of a foundation wall, upon which the floor
joists rest.

SLEEPER
A wood member embedded in concrete, as in a floor, that serves to support and to
fasten subfloor or flooring.

SMOKE PIPE
A pipe conveying products of combustion from a solid or liquid fuel-fired appliance
to a chimney flue.

SOFFIT
The horizontal or sloping part of the eave.

30
REED GLOSSARY OF HOUSING TERMS

SOIL COVER (GROUND COVER)

A light covering of plastic film, roll roofing, or similar material used over the soil in
crawl spaces of buildings to minimize moisture permeation of the area.

SOIL STACK
A general term for the vertical main of a system of soil, waste or vent piping.

SOLAR ALTITUDE
The angle of the sun above the horizon measured in a vertical plane.

SOLAR ENERGY
Energy in the form of electromagnetic radiation received from the sun.

SOLAR RADIATION
Electromagnetic radiation emitted by the sun.

SOLE OR SOLE PLATE

See PLATE.

SOLID BRIDGING
A solid member placed between adjacent floor joists near the center of the span to
prevent joists from twisting.

SPAN
The horizontal distance between supports for beams, joists, rafters, etc.

SPECIFIC HEAT
The number of BTU's required to raise the temperature of one pound of a substance
1°F in temperature.

SPLASH BLOCK
A small masonry block laid with the top close to the ground surface to receive roof
drainage and divert it away from the building.

SQUARE
A unit of measure usually applied to roofing material.

STACK EFFECT
Pressure differential across a building caused by differences in the density of the air
due to an indoor-outdoor temperature difference.

STILE
The vertical edge members of a window sash.

31
REED GLOSSARY OF HOUSING TERMS

STOREY
The part of a building between any floor and the floor or roof next above.

STORM DOOR
An extra outside door for protection against inclement weather.

STORM SASH OR STORM WINDOW

An extra window usually placed on the outside of an existing one as additional
protection against cold weather.

STRATIFICATION
The formation of layers in the air where the top layer is warmer than the bottom.

STRING, STRINGER
A timber or other support for cross members in floors or ceilings. In stairs, the support
on which the stair treads rest; also stringboard.

STRUT
A structural member which is designed to resist longitudinal compressive stress such
as members supporting a ridge beam or rafters; a short column.

STUCCO
An outside plaster made with Portland cement as its base.

STUDS
The vertical framing members between the posts used to support vertical loads and
provide nailing surfaces for interior and exterior sheathing.

SUBFLOOR
The boards or sheet material laid on joists under a finished floor.

SURFACED LUMBER
Any lumber that has been planed after sawing.

SUSPENDED CEILING
A ceiling system supported by hanging it from the overhead structural framing.

T
TAIL BEAM
A relatively short beam or joist supported in a wall on one end and by a header at the
other.

32
REED GLOSSARY OF HOUSING TERMS

THERMAL BREAK (THERMAL BARRIER)

An element of low heat conductivity placed in such a way as to reduce or prevent the
flow of heat.

THERMAL BRIDGE
A low thermal resistance path connecting two surfaces; for example, framing
members in insulated frame walls or metal ties in cavity wall and panel construction.

THERMOSTAT
Any device that controls a heating or cooling device by responding to changes in
temperature.

THRESHOLD
A strip of wood or metal with bevelled edges used over the finish floor and the sill of
exterior doors.

TIE BEAM
A beam connecting the base of rafter pairs to prevent outward thrust.

TIMBERS
All wood framing members whose smallest dimension is 5 inches (127 mm).

TOENAILING
The practice of nailing at an angle to the first member so as to ensure penetration
into a second member.

TONGUE-AND-GROOVE LUMBER
Any lumber, such as boards or planks, machined in such a manner that there is a
groove on one edge and a corresponding tongue on the other.

TOP PLATE
The horizontal member nailed to the top of the partition or wall studs in a building.

TRANSOM
A horizontal member separating a door from a window panel above the door, or
separating one window above another.

TRIM
The finish materials in a building, such as mouldings, applied around openings
(window trim, door trim) or at the floor and ceiling of rooms (baseboard, cornice and
other mouldings).

TRIMMER
A beam or joist alongside an opening and into which a header is framed.

33
REED GLOSSARY OF HOUSING TERMS

TRUSS
Any rafter, ceiling joist and tie assembled in such a way as to span a greater distance
than the rafter alone.

U
U-VALUE
(Coefficient of heat transfer)
Imperial : The number of BTU's that flow through one square foot of a material in one
hour, when there is a 1°F difference in temperature between the inside and outside
air, under steady state conditions.
Metric : The number of watts that flow through one square metre of a material in one
hour, when there is a 1°C difference in temperature between the inside and outside
air, under steady state conditions.
The U-value is the reciprocal of the resistance or R-value.

V
VALLEY
The internal angle formed by the junction of two sloping sides of a roof.

VALLEY RAFTERS
Any rafters which are located at the centre of roof valleys to support the jack rafters.

VAPOUR BARRIER
The material used to retard the movement of water vapour into walls and attics and
prevent condensation in them. Applied separately over the warm side of exposed
walls.

VAPOUR DIFFUSION
The movement of water vapour between 2 areas caused by a difference in vapour
pressure, independent of air movement. The rate of diffusion is determined by 1) the
difference in vapour pressure, 2) the distance the vapour must travel, and 3) the
permeability of the material to water vapour. Hence the selection of materials of low
permeability for use as vapour retarders in buildings.

VAPOUR PRESSURE
The pressure exerted by a vapour either by itself or in a mixture of gases. For
example, when referring to water vapour, the vapour pressure is determined by the
concentration of water vapour in the air.

34
REED GLOSSARY OF HOUSING TERMS

VARNISH
A thickened preparation of drying oil or drying oil and resin suitable for spreading on
surfaces to form continuous, transparent coatings, or for mixing with pigments to
make enamels.

VENT
A pipe or duct which allows a flow of air or gas as an inlet or outlet.

VENTILATION
The provision for supplying, moving or removing air, either mechanically or naturally.

VERMICULITE
A mineral closely related to mica, with the faculty of expanding on heating to form
lightweight material with insulation quality. Used as bulk insulation, as aggregate in
insulating and acoustical plaster and in insulating concrete floors.

VISIBLE LIGHT
The light in the electromagnetic spectrum with wavelengths ranging from 400 (blue)
to 700 (red) millimicrons.

W
WALL PLATES
The horizontal members in wood frame construction attached to the ends of the
studs. Also called top or bottom plates, depending on their location.

WATER-REPELLENT PRESERVATIVE
A liquid designed to penetrate into wood and impart water repellency and a moderate
preservative protection. It is used for millwork, such as sash and frames, and is
usually applied by dipping.

WATER TABLE
The level below which the ground is saturated with water.

WATER WALL
An interior wall of water filled containers constituting a one step heating system
which combines collection and storage.

WEATHER BARRIER
The outer most assembly of the building envelope, used to protect the inner structure
and insulation from the effects of wind and rain. Materials typically used are siding,
building paper and flashing.

35
REED GLOSSARY OF HOUSING TERMS

WEATHERSTRIPPING
A strip of felt, rubber, metal or other material, fixed along the edges of doors or
windows to keep out drafts and reduce heat loss.

WEEP CUT (DRIP CUT)

A groove in the underside of a horizontal board or masonry unit (such as a sill), which
projects beyond the wall surface below to prevent water from moving back towards
the wall surface.

WEEPHOLE
A small hole, as at the bottom of a retaining wall or masonry veneer, to drain water
to the exposed face.

WIND BREAK
A hedge, fence or row of trees that serves as a protection from wind.

WIND ENERGY
The kinetic energy of air motion over the earth's surface caused by the sun's heating
of the atmosphere.

WINDOW, PARTS OF
Balance : A device used to counteract the weight of the sash for ease of operation.
Light : Window pane; the term is used to designate the number of separate panes
which make up the entire window.
Lintel : The horizontal top piece of the window framework.
Mullion : The perpendicular members which divide the bays or lights of windows or
screen-work.
Muntin : A secondary framing member (horizontal, vertical or slanted) to hold the
window panes in the sash. This term is often confused with Mullion.
Pane : A glass surface in a window. A window may include a number of panes or
may consist of a single pane.
Rough Frame : Framing of the enclosure in which the finished window frame is
placed.
Sash : A light frame of wood, metal or plastic either fixed or movable which holds the
glass.
Sill : The base of the window frame sloped on the outside to shed rain.

36
REED GLOSSARY OF HOUSING TERMS

WINDOW TYPES
Awning Window : A frame containing one or more sash, each of which is installed
in a vertical plane and is hinged to permit the bottom of the sash to open outward.
Bay Window : Window which projects outside the main line of a building and the
compartment in which it is located.
Casement Window : A frame which contains a sash hinged at the side to open in or
out.
Check Rail Window : A frame containing at least a pair of sash which are engaged
when closed. The sash are installed in a vertical plane and designed to be moved
either vertically or horizontally.
Clerestory Window : A window which occurs in the wall of a clerestory.
Dormer Window : A vertical window in a dormer for lighting a room adjoining a
sloping roof.
Double-Hung Window : A window with an upper and lower sash, each balanced by
springs or weights to be capable of vertical movement with relatively little effort.
Fire Window : A window with its frame, sash and glazing which, under standard test
conditions, meets the fire protection requirements for the location in which it is to be
used.
Hopper Window : A frame containing one or more sash, each of which is installed
in a vertical plane and hinged to permit the top of the sash to open inwards.
Jalousie Window : A frame containing a number of movable, shutter-like,
overlapping glass panels.
Oriel Window : A window or group of windows that projects beyond the wall of a
building and is usually carried on brackets or corbels.
Sashless Window : A window with a wood frame containing at least two lights of
glass with polished or ground edges, or sash with light metal or plastic edges. At
least one light of glass slides horizontally or vertically.

WOOD FRAMING
Balloon Framing : A method of wood frame construction in which the studs extend
in one piece from the foundation wall to the top plate supporting the roof.
Bridging : A method used to resist twisting of joists and for stiffening floor
construction by fitting either crossed pieces or solid blocks between the joists.
Cap : The upper half of the top plate in wood frame walls and partitions.
Plank Framing : A type of construction which employs flat vertical structural
members with horizontal beams let into them and having an infilling of planks on
edge.
Post and Beam Framing : A system of construction in which posts and beams
support the loads and the infilling walls are non-load bearing.
Western Framing (Platform Framing) : A system of framing a building on which
floor joists of each storey rest on the top plates of the storey below (or on the
foundation sill for the first storey) and the bearing walls and partitions rest on the
subfloor of each storey.

37
REED GLOSSARY OF HOUSING TERMS

WYTHE
A continuous vertical section of a masonry wall having a thickness of one masonry
unit.

38
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