


Access route

A continuous route for a fire escape path that permits people and goods to move between the apron or construction edge of the building to spaces within a building, and between spaces within a building.

Acoustic Installation (sound insulation)

Means taken to reduce the transmission of sound between household units predominantly in multi-unit buildings.

Acrylic paint

A coating material made with acrylic resins as the main base.


Synthetic resin used to hold surfaces together rather than bond them as in glue bonding.


A material other than cement, aggregate, or water added to concrete or plaster to modify its



Inert material which is mixed with Portland cement and water to produce concrete or plaster.

Air gap

The vertical distance through air between the lowest point of the water supply outlet and the flood level rim of the equipment or the fixture into which the outlet discharges.


Pipe or valve for allowing free escape of air.

Alkyd resin

A processed natural oil which is widely used as a vehicle in the manufacture of paints and varnishes.


A moulding surrounding a door or window opening.


The rounding of a sharp edge usually formed by any two surfaces meeting at an angle.

Asbestos cement

Cement mixed with asbestos fibre, previously used in the manufacture of roof and wall claddings and rain-water goods. (This material is no longer used).


Natural bituminous material, which can also be made by distilling petroleum. The distinction between asphalt and bitumen is vague but in general the world ‘asphalt’ is used in connection with solid surfacing and ‘bitumen’ in connection with liquids suitable for coating aggregates.


Habitable room entirely within the roof space of a building





A flowing back or reversal of the normal direction of the flow of water in plumbing pipes caused by back pressure and includes back-siphonage.


Platform enclosed by a railing or balustrade, projecting from or recessed into the face of a wall of a building or structure.


A post providing the support for the top and bottom rails of a barrier.


The infill parts of a barrier (typically between floor and top rail).

Barge board

A board fixed along the edges of a gable or lean-to and covering the ends of roof members and overlapping the cladding below.

Base coat

Plaster coat applied prior to application of the subsequent coats.


The quantity of concrete or mortar mixed at one time.


A pad of thermal insulation material.


A piece of sawn or dressed timber of rectangular cross-section usually between 20mm and 40mm thick and between 25mm and 75mm wide.

Beam, flitched

A built-up rectangular beam in timber work, composed of two or more pieces bolted together side by side. When of three pieces the middle one is usually a steel plate.

Beam, secondary

A beam that transfers its load to the main or primary beam.


A beam supported on jack stud, foundation walls, piles or piers and carrying joists, jack studs or subfloor framing.


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

Birdsmouth joint (timber)

An angle checked near or at the lower end of a rafter to provide a supporting junction point for connection to the wall plate.

Bituminous felt

Felt impregnated with bitumen.

Board and batten

Vertical boarding to cover a wall with the vertical joints covered by battens.

Bolt, carriage (coach bolt)

Bolt with a squared neck and usually with a mushroom head. This enables it to grip wood without turning as the nut is tightened.

Bolt, countersunk

Bolt having a conical head which will sink flush with the material.

Bolt, expansion

A bolt having an expanding device increasing the diameter of the inner end to form a wedge grip.

Bond beam

Masonry courses containing horizontal reinforcement.

Bond breaker

A release surface to which the sealant will not adhere.

Boron (H1.2)

Sodium borate based treatment process for insects and decay prevention.

Bottom Plate

The lower horizontal member of a timber frame.

Bottom Vented Rainscreen

A cavity behind a cladding that allows mainly free vertical drainage that has a vent at the bottom only.

Building paper, breather type (Bituminous of synthetic)

Building paper which provides an acceptable permeability to water vapour (that is, will transmit water vapour).

Building Paper or Wrap

A breather paper or synthetic thin sheet material used as a backing component to external cladding.





Projecting hood supported on brackets, corbels or columns over a door, window or niche.


Member fixed at one end and ~ section but not supported at the other end.

Cantilevered pile

A pile directly supporting a bearer and embedded into the ground so as to resist horizontal loads.

Capillary gap/leak

A gap between building elements wide enough to prevent capillary uplift.


The head of a column or pilaster immediately under a beam.


Window sash hinged or pivoted in the vertical plane.

Cathedic Protection

Sacraficial metal usually electrapated onto other metals to reduce corrosion of the protected main metal component.


The space between a skin of masonry and an adjacent skin or wall.

Cavity System

A formed gap between building elements.

Cavity wall

A wall built or two or more skins of masonry units arranged to provide a continuous air space between the skins.

CCA (H3.2, H4 and H5)

Copper Chrome Arsenic used mainly as a timber decay preservative

Ceiling batten

A horizontal timber member fixed below rafters, ceiling joists or truss bottom chords to which the ceiling lining is attached.

Ceiling, coved

  1. Ceiling springing from the walls with a curve.
  2. Inclined ceiling such as that formed on the under surface of rafters.

Ceiling, suspended

Ceiling hung at a distance from the floor or roof above and not bearing on the walls. Generally used to conceal services.

Certificate of Title (COT)

Document formally attesting to rights of ownership to a piece of land, held for all private (and most publicly owned) land in Lands and Deeds Registry Offices. Includes details of owners, type of ownership, area, legal description, mortgages, charges, leases and all easement and other conditions. Record open to public search with facsimile copy obtainable for fee.

Chamber, inspection

Chamber formed at points in the length of a drain or sewer in order to give access for purposes of inspection.


A corner beveled at 45 degrees.

Chamfer, stopped (stop chamfer)

A chamfer stopped at one or both ends with a splayed or moulded cut, leaving the portion not chamfered of rectangular form.


Long groove or recess formed in a constructed wall. Often used to accommodate flashings.

Chemset Bolt

A bolt fitted into a hole that relies on a chemical bond to hold it in place.


The top or bottom member of a framed beam or truss.


Covered vessel containing water, the supply being regulated by a float controlled valve, generally for the flushing of sanitary fixtures. Is also applied to the supply tank for a hot water cylinder where this is built into the cylinder casing.


The exterior weather-resistant surface of a building.

Clashing strip

Strip fixed on the edge of a flush door.

Code Compliance Certificate

A certificate provided by Building Consent Authority (normally councils) notifying that they are satisfied on reasonable grounds that building work has been completed in accordance with a building consent and in compliance with the building code.

Collar tie

A horizontal member connecting paired rafters together at intermediate points between the ceiling level and the level of the ridgeboard. It is often fixed directly above the underpurlins.


The process of producing a closer packing of particles by rolling or other mechanical means or by hydraulic compression.


  1. Two or more paint or varnishes which can be mixed without producing an undesirable effect.
  2. Different coats of paint which can be associated in a painting system or other coating systems without producing undesirable effects.
  3. Metal types that do not set up electrolytic action.
  4. Building materials that can be safely used in conjunction with each other.

Compliance schedule

A schedule issued by a territorial authority, specifying the inspection, maintenance and reporting procedures to be followed for specific systems in a building.

Concept Design

The early design thoughts and possibilities.

Concrete, aerated

A lightweight concrete made by introducing air cells, or by generating other gas, in a slurry of Portland cement and water, which may also contain lime as well as a siliceous mineral filler, so that a uniform cellular structure of the required density is formed on hardening.

Concrete, prestressed

Concrete in which effective internal stresses are induced artificially usually by means of tensioned steel wire or rods, prior to loading the structure.

Concrete screed

A concrete layer applied to a base and suitably finished to receive flooring at a designated level.

Concrete topping

Concrete laid on a concrete base to provide a wearing surface.

Condensation gutter

Small gutter, usually made on the inside of skylights or windows, to collect condensation water.


The ability of an element to allow electrical current to flow through it.

Conductivity (K value)

The thermal conductivity of a substance is the amount f heat in watts passed through an area of one square metre, one metre thick, in one hour under a temperature difference of 1oC between the two sides. For constructional materials as whole there is roughly proportional relationship between conductivity and density.


  1. Channel or pipe to convey water.
  2. Tubing used as a casing for electrical cables or wires.

Connection (in cavities)

The outflow and inflow of air into cavities owing to changes in the external air pressure.

Construction joint

Generally a joint between one pour which has been completed and allowed to harden and another pour placed against it.

Contingency sum

An allowance of money provided in addition to a contract price to cover unknown or unpredictable matters.

Contract price

The sum named in the tender, subject to such additions and deductions as may be made under the provisions of the contract.


The person whose tender has been accepted by the principal to undertake work named in the contract.

Construction Contracts Act

An act of parliament providing a quick dispute resolution proceed and rules for resolution of payment and technical issues that can occur during a building contract.


Stone, brick or concrete covering to the top of a wall exposed to the weather. Designed to throw off the water, it should be preferably be wider than the wall, with drips cut in its projecting under-surfaces.


Projecting support either isolated or continuous from the face of a wall or column.


  1. Projecting mouldings at the top of a wall or eaves or at the top of framed openings.
  2. A mould placed at the junction of wall and ceilings.


The breakdown of metals by air, water, salts, geothermal gases or industrial pollutants.


To prepare a screw or bolt hole so that the head of the screw or bolt will be flush with, or below, the face of the material.


Horizontal layer of bricks, stones or blocks, or a row of slates or tiles.

Course, soldier

A course of bricks set on end, laid usually as a coping.

Course, stretcher

A course of stretchers or one which shows stretchers on the face.

Cove (coving)

Rounded concave junction between a horizontal and a vertical surface.


  1. Fine random cracks or fissures caused by shrinkage which may appear in a surface of plaster, cement paste mortar, concrete, paint or membranes.
  2. Formation of hairline cracks in a glaze on ceramics.


Slow deformation or movement of a material under stress.


Process adopted to ensure hardening of cement, plaster and cement products by preventing or controlling excessive evaporation or extremes of temperature. Steam may be used to hasten the process.





A horizontal mid wall change in wall surface material.

Dado rail

Rail situated at the junction of the dado and the upper portion of the wall surface.


Making a structure water-resistant and proof against dampness by special materials or processes.


A clearly defined and accessible level marker from which the required levels of a building or its site can be readily measured during construction.


A heavy block or structural member sometimes buried, to which a guy or a tie member is secured.


Decomposition of wood by fungi.

Defect, permissible

A defect that does not exclude a building element from being accepted in a defined grade.

Deformed bar (‘D’)

A deformed reinforcing bar of the stated diameter in millimeters

Deposited Plan (DP)

Survey plan giving legal definition to property boundaries. Required to be placed with and held by the District Lands Information Registrar before issue of title. Facsimile copy available for public inspection and purchase.

Detailed Design

Drawings showing all elevations, cross sections and specific design information.


The removal of water from the ground, for example, the pumping out of a drowned caisson or foundation.

Diagonal brace

A member of a framed building fixed diagonally and used to resist tension or compression or both.

Di Electrical Field

The electrical field emitted by various building products.

Differential Movement

The thermal movement difference of various building elements


Slow water vapour dispersal through building elements.

District plan

Plan prepared in terms of the Resource Management Act by a territorial authority. Available for public inspection at places that may be nominated by the authority (generally the authority’s office and public libraries within the district).

Door closers

Spring or hydraulic devices which control the opening and closing speed of a door.

Door, fire

A doorset, single or multileaf identical in assembly construction and installation with a production model that has been submitted to the standard fire resistance test and has fulfilled all the relevant test requirements.

Door, flush

A door which has unbroken plan faces.

Door frame

A frame for a door usually consisting of two jambs and a head, and sometimes a transom. A sill may be included for an outer door.

Door head

The portion of the door frame over the top of the door.

Door, hollow core

Flush door having a substantially hollow core.

Door sill

A horizontal member forming the threshold of the doorway.

Door, solid core

Flush door having a solid core.

Double glazing

Glazing that incorporates two panels separated with sealed air space for the purpose of sound insulation or thermal insulation, or both.

Dragon tie

A horizontal tie placed across the wall plates at the corner of a building to support the inner end of a dragon beam and prevent the walls from spreading. Also called “Angel Tie”.

Drain, field (subsoil drain)

An open-jointed drain for the collection and removal of ground water. Subsoil drains are also made of perforated pipes.

Drain Vented Cavity

A cavity behind a cladding that allows mainly free vertical drainage and has vents at its top and bottom.


Separation of layers in cement plaster, ceramics and tiled work.

Dry riser

Vertical water main, normally empty, fixed inside a building with an inlet or inlets at street level, through which water can be pumped to hydrant outlets at the various levels.

Durability (building)

Resistance to wear and decay.

Durability (paint)

The lasting quality of paint under the conditions to which it is subjected.




Eaves (cave)

The lower part of a roof projecting beyond the face of a wall.

Eaves soffit

Horizontal or inclined surface under eaves.


The formation of a white crystalline deposit on the surface of concrete brickwork, masonry or plaster due to the evaporation and crystallization of the alkaline salts which may be contained in the building materials.


Apparent homogeneous material formed by the incorporation of two liquids which are normally immiscible. One liquid is dispersed in the other in the form of minute droplets. If the droplets remain permanently dispersed the emulsion is said to be stable and certain compounds called emulsifiers that keep the droplets dispersed are added as stabilizers.

Enamel (paint)

Normally oil based, in the paint industry the term is also applied to describe pigmented alkyd varnishes which forma hard glass surface.

Escutcheon, keyhole

Shield fixed to a surface of a door primarily to protect the door from wear or damage b continued insertion of the key, but often also serving a decorative purpose.


Calculated costs of a construction project based on a design proposal and using comparisons with similar projects to establish budgets prior to final pricing.

Exotic timber

Species of timber such as Radiata pine and Douglas Fin originally introduced to New Zealand from overseas forests.

Expansion joint

Joint arranged between sections of wall, floors, roof etc to allow them to expand or contract with rise or fall of temperature.

External wall

Any exterior face of a building within 30% of vertical. Consisting of primary and/or secondary elements intended to provide protection against the outdoor environment, but which may also contain unprotected areas. (NZBC).





The face, or front, of a building.

Factor of safety

The ratio of the ultimate strength (or yield point) of a material to the working stress assumed in design (Stress factor of safety); or the ratio of the ultimate load, moment, or shear of a structural member to the working load, moment or shear respectively, assumed in design (Load factor of safety).


A board fixed horizontally to the lower ends of the rafters to which spouting may be fixed. Also forms the outside board of a boxed eave.


Thinning out edges; the diminishing edge.


Board made from fibrous material such as wood pulp. Can be low, medium or high destiny.

Fibre Comment

(Refer to Board, fibre)


Small angle moulding or strip formed in wood, stone, concrete or plaster.

Finger joint

Self-locking end joints formed by machining a number of similar tapered symmetrical fingers in the ends of timber members which are then bonded together.


A pointed ornament fixed vertically at the apex of a gable or spire.

Finish coat

The final coat of plaster, modified plaster and paint.

Finished ground level

The level after all backfilling, landscaping and/or surface paving has been completed.

Fire partition

Partition of specified grade of fire resistance.

Fire resistance rating (FRR)

The terms used to classify fire resistance of primary and secondary elements as determined in the standard test for fire resistance, or in accordance with a specific calculation method verified by experiment data from standard fire resistance tests. It comprises three numbers giving the time in minutes for which each of the criteria stability, integrity and insulation are satisfied and is presented always in that order.


The upper or lower part of a rolled steel joist universal beam or girder.

Flanking coat (plastering)

An intermediate leveling coat of plaster in between bond or scratch coat and finish coat.


Coated Galvanised steel or other impervious material used in parts of a building to prevent penetration of moisture where different components meet.

Flashing, apron (counter flashing)

The over-flashing fixed into a vertical surface to cover the up-stand of a flashing on a sloping or a flat surface.

Floor waste

A discharge pipe with a graded inlet located at the lowest point within a graded floor, and which conveys accidental overflows of waste water to either the outside of the building or to the foul water drainage or the plumbing system. (NZBC).


  1. The passage through which the products of combustion are conveyed to the outside.
  2. An enclosed continuous horizontal or vertical space in a masonry element formed by the cells of the masonry units which make up that member. (NZBC).


  1. Adjoining surfaces in the same plane or level.
  2. To clear a drain or a sanitary appliance by a flow of water.

Flush box

Outlet box recessed into a wall or partition for accommodating accessories connected to the fixed wiring. The front of the accessory is approximately flush with the wall surface.

Flush joint

Joint stopped and finished to provide a continuous surface.


That portion of a foundation bearing on the ground and any adjoining portion that is reinforced so as to the ground the bearing forces. It may be spread out to provide an increase in bearing area or an increase in stability.

Formwork (shuttering)

Total system of support for freshly placed concrete including the mould or sheathing which contacts the concrete as well as all supporting members, hardware and necessary bracing.

Foul water

The discharge from any sanitary fixture or sanitary appliance. (NZBC).


Those parts of a building or structure such as piles, piers or footings which transmit and distribute loads to the ground.

Foundation, raft

A continuous concrete slab usually reinforced, constructed over soft ground.

Frame, portal

A frame of steel, reinforced concrete or timber constructed with rigid joints for stability without diagonal bracing.

Framing timber

Timber members to which lining, cladding, flooring or deck is attached or which are depended upon for supporting the structure or for resisting forces applied to it.


  1. Surface between the architrave and cornice.
  2. Upper part of a wall immediately below the cornice.

Frieze panel

Top horizontal panel in a door having one or several panels below, or the top panel in a length of paneling.


See fire resistance rating.


Chemicals used to control fungal growth.


A growth (for example, mould, mushroom) devoid of chlorophyll, composed of hyphae and reproduced by minute spores borne on a fruiting body.





Outside wall between the planes of the roof and the line of the eaves.


To coat iron or steel with zinc by hot dripping or similar process.


An item of packing material usually preshaped and used to make an effective seal at a flanged or other type of joint.


Running sawn timber through a machine (saws or planer), to reduce both thickness and width to a uniform standard.


Horizontal secondary structural members to which side wall sheathing is attached.


  1. The horizontal distance from face to face of consecutive risers in a stair.
  2. The total horizontal distance from the face of the first riser tot eh face of the last riser.

Grade (Timber)

  1. An established quality or use classification of timber or timber products.
  2. To sort timber into different established classes according to quality or use.


Gradient is the relation between the horizontal distance and the associated change of level. The measure used is the tangent of the slope angle with the vertical displacement always expressed as unit or as a tangent ratio expressed as a percentage, for example 1 in (or on) 50, or 2 percent.

Grading rules

Any generally accepted set of rules providing for the classification of timber by defining the nature and extent of blemishes and defects permissible I each class or grade.

Grease trap

A device designed to intercept grease in a foul water discharge.

Green (timber)

Unseasoned, wet, with free water present in the cell cavities.

Gully trap

A fitting designed to prevent foul air escaping from the drainage system and used to receive the discharge from waste pipes.


Channel for draining water at the sides of a road, or off a roof, or from any surface.

Gutter, parapet

Gutter constructed behind a parapet wall.





Brick with its longer axis at right angles to the face of the wall.

Heavy roof

A roof with roofing material (cladding an any sarking) having a mass exceeding 20kg but not exceeding 60kg per square metre of roof area.

Heavy wall cladding

A wall cladding having a mass exceeding 80kg pre square metre but not exceeding 220kg per square metre of wall area which are supported on their own foundations or foundations supporting timber frame (typical examples are clay and concrete masonry veneers).

Hight Reflectance Values (Check)

Hinge, piano

A butt hinge which extends the whole length of the moving part.


The external angle formed by the intersection of two inclined roof surfaces. The opposite of valley.


The rejection of water


The pressure applied to surfaces by a head of contained water.

Hygroscopic The vapour transmission of water into building products.




Indigenous timber

Species of timber growing naturally in New Zealand (for example Rimu, Matai, Tawa and certain beeches).

In situ

Latin for ‘in place’ referring to materials or components that are cast or assembled in their permanent position in a building or structure as distinct from being cast or assembled before installation.

Interlocking concrete block paving

A pavement structure comprising a surface course on interlocked concrete paving blocks with sand filling in joints between blocks and bedding course, a base-course, a sub-base (depending on subgrade and traffic loading condition), the subgrade and edge restraint.


The lowest part of the inner surface of a sewer, pipe channel or tunnel.




Jack stud

A stud of less length than the full height from plate of the wall of which it forms part, or a stud at pile spacing forming part of the supporting framing under the ground floor of a building.


A vertical side member of a door frame, door lining or window frame.

Joint, bed

A horizontal mortar joint between two courses of bricks or masonry.

Joint, mitre

A joint in which the line of junction bisects the angle, usually a right angle, between the two pieces.

Joint, mortise and tenon

In which a tenon on the end of one member is fitted into a mortise cut in the other member.

Joint, scribed

A joint between two intersecting members in which one piece is cut to fit on to the profile of the other piece.


A horizontal framing member to which is fixed floor decking or ceiling linings and which is identified accordingly as a floor joist or ceiling joist.

Joist boundary (or header joist)

A joist running along the outer ends of the floor joists.

Junction box

A box or casing by which electrical conduit branches are joined, or a box containing terminals for the connection of branch conductors.





Seasoned in a kiln usually to a specified or selected moisture content.





Fixes plaster layer to the/its structural supports and to resist shrinkage movement.

Lath, rib

Expanded metal lath which is formed with stiffening ribs.

Leaching (Timber Preservative Treatment)

The loss of a treatment owing to the presence of water across to an associated product.

Lead edging

Thin strip of lead fixed to the outer edge of galvanized roofing or flashing to provide a joint that follows the profile of the sheeting.

Life Cycle Cost

The cost over a material over a given time including its original cost and maintenance of replacement.

Light Reflectance Values

The amount of light that is reflected off various different colours.

Light roof

A roof with roofing material (cladding and any sarking) having a mass not exceeding 20kg per square metre of roof area (typical examples are steel, copper and aluminium roof claddings of normal thickness, 6mm thick cellulose cement tiles, 6mm thick corrugated cellulose cement and the like, without sarking).

Light wall cladding

A wall cladding having a mass not exceeding 30kg per square metre (typical examples are weatherboards).

Lightweight masonry

Concrete masonry produced from lightweight aggregate such as pumice or aerated concrete.

Lining, soffit

Lining on the underside of any horizontal or sloping surface normally below roof or decks.


Short length of steel bent round intermediate reinforcing rods of concrete columns.


A horizontal member spanning an opening and provides support to constructions above.

Loadbearing wall

A wall supporting vertical loading from floors, ceiling joists, roof or any combination thereof.

Load, dead

The weight of the structure and any permanent loads fixed thereon.

Load, distributed

Load spread over an area or length, and not necessarily uniform.

Load, live

Loads assumed or known to result from the use of occupancy of a structure. It does not include earthquake, wind, snow or other environmentally induced loads.

Load, safe

See Factor of safety.

Long run roofing

Overlap profiled rigid sheet metal runs the full length of the pitch of a roof without end laps.

LOSP (H1.2 and H3.1)

Light Oil Salt Preservative or white spirits carry timber treatment into timber.


A screen of sloping slats usually horizontal and may be adjustable to shut out light and allow ventilation.


Projection from a fitting for fixing purposes.





The principal sewer or stormwater drain into which individual drains discharge. Principle electric cable or pipe bringing power, water or gas to a building.


The electrical equipment forming part of an electrical installation that is used for the supply of electricity to the main switchboard of that installation.


Covering that part of a surface to which it is not desired to apply paint.


A person skilled in the construction of masonry.


Any construction in units of fired clay, concrete or stone laid to a bond in and joined together with mortar.

Masonry, reinforced

Any masonry in which reinforcing steel is so bedded and bonded that the two materials act together in resisting forces.


Any of a wide variety of pliable materials generally oily or bituminous nature, for pointing, setting or packing to exclude moisture.


Tongued and grooved boards generally with edges beaded or V-jointed. Used for internal ceiling or wall lining.


Cement paste in which the sand particles of a mortar are embedded, or the mortar in which the aggregates of concrete are embedded.

Medium wall cladding

A wall cladding having a mass exceeding 30kg per square metre but not exceeding 80kg per square metre of wall area (a typical example is stucco cladding).

Mezzanine floor

A part storey usually in the form of a balcony or platform between two main storeys of a building.

Mix (concrete)

The proportions of aggregates, sand, cement and water to make a particular concrete mixture.

Moisture content equilibrium (timber)

The moisture content at which timber neither gains nor loses moisture when subject to given conditions of humidity and temperature.


Formed of a single stone or cast to form a structurally continuous mass. Presents like a seamless wall cladding.


A mixture of cement, lime, sand and water with or without chemical admixtures, used for the laying of masonry units and which binds them together after hardening. If the quantity of cement is great than the quantity of cement is greater than the quantity of lime, the mix is a cement mortar. When less cement to lime is used or when lime alone is used, the mix is known as a lime mortar.


A superficial growth of fungus which usually appears in the form of a woolly or furry coating.


Any long strip of trim material of small profile, and may contain channels, curves or rounds. A moulding may be manufactured from joinery run timbers, or from plastics or metal, by casting, tooling or extruding.

Movement control joint

A joint designed to prevent damage to walls due to shrinkage, temperature and other movements.


An intermediate vertical member of a window frame, door frame or similar structure.

Multi-unit dwelling

Applies to a building or use which contains more than one separate household.




Nail, clout

Nail with a relatively large flat disc head, frequently galvanized, and usually in sizes from 13mm to 40mm.

Nail, flat head

Nail with a flat disc head used for greater holding power in soft materials.

Nail, jolt head

A nail with a stubby head.

Nail, lead-head

Nail having a lead, cup-shaped head which makes a fastening water-resistant between the roofing and the nail, by the cup deforming to the profile of the roofing.

Nail, spring-head

Nail having a circular, concave, light metal head used in the same way as lead-head nails.

Nailing, skew

The operation of driving nails obliquely.

Natural ground level

The ground level before the site levels have been altered.

Neutral axis

A line in the plane of a structural member subject to bending where the longitudinal stress is zero.


  1. Upright post fixed at the foot or head of a stair or at a point of change of direction. It often supports a balustrade or handrail.
  2. The central column carrying the inner ends of the steps in a spiral stair.


  1. Small projection on a wall, floor or other surface.
  2. Small projection on a casting for fixing purposes, as on a roof tile.

Noggin or nog

(See Dwang)

Nominated subcontractors

Those subcontractors who are usually selected by the Architect, Engineer or client representative administering the works, for specialist sections of the project.

Non-loadbearing stud

A stud in a non-loadbearing wall that simply acts as a partition.

Non-loadbearing wall

A wall other than a loadbearing wall.


The rounded projecting edge of a stair tread.

Nut, lock

  1. Auxiliary nut used in conjunction with another to prevent it from loosening under vibration.
  2. Any special type of nut designed to obviate accidental loosening, for example a castle nut.




Off-the-form concrete

Concrete which is formed by placing and stripping from formwork and has no other applied finish.

Ordinary pile

A pile that does not have a diagonal brace attached to it and that is required to resist vertical loads only.


Minor building (such as a bach or shed) which may be attached to a main building but to which the access is from the outside.


Will not lose moisture in a ventilated oven at a temperature between 100 degrees Celsius and 105 degrees Celsius.





  1. Any material used for filling, leveling or making solid under or between members.
  2. Compressible material such as hemp or special proprietary packings inserted in joints to make them watertight.

Paint performance


Migration of a dye or stain from stained wood or an undercoat into subsequent coats.


Board made from particles of wood or other lignocellulosic material bonded with synthetic resin or other organic binder.


Valance or shielding at the head of a window or door to hide the fittings of blinds and curtains.


The vertical joints in brick or blockwork. Term also used for slating or other bonded materials.


A block or a column like member penetrating the ground and used to transmit loads from the building and its contents to the ground.

Pinehole (timber)

Hole not larger than 1mm in diameter, usually darkly stained and which does not contain borer dust. The insects which make these holes do not attack or continue to work in thoroughly seasoned timber.


The inclination of the roof or any part of a building to the horizontal.


Cementitious material or combination of cementitious materials and aggregate that when mixed with water forms a plastic mass which sets or hardens after application to a surface.

Plaster, fibrous

Plasterboard product usually in sheet form containing fibrous material as a reinforcement.


A substance of low volatility incorporated in a plastic material such as wet concrete to increase its flexibility for ease of processing and “flowability”.


Slight widening or thickening, projecting at the bottom of a wall, pedestal or column.


A term for ‘vertical’, to make vertical.


Finishing previously raked joints of brickwork or masonry with ordinary mortar or with a special mortar.

Polyester resins

Plastic made by interaction of certain organic acids with alcohol and used in coatings (e.g. alkyd resin) or when reinforced (e.g. with glass fibres) for structural purposes.

Polyethylene or polythene

A thermoplastic material formed by the reaction and linking of the ethylene molecule, which is light, strong, water resistant and flexible even at low temperatures. It is used in sheeting, foil, vapour barriers and pipes and pipe fittings.


A thermoplastic material, formed by the reaction and linking of styrene molecules, which are lightweight, water resistant, dimensionally stable, easily moulded and transparent but begins to soften near the boiling point of water (100 degrees Celsius).

Polyurethane resins

Polymerized urethane used for casting and coatings frequently supplied in two packs to be mixed immediately before use.

Polyvinyl chloride (PVC)

A thermoplastic material, formed by the reaction and linking of vinyl chloride molecules, used for resilient flooring, waterproof membranes, pipes etc. It is also available as a rigid or flexible foam.


A method of stressing thereby reinforcing, in which the tendons are tensioned after the concrete has attained sufficient strength and then locked in by grouting.

Potable water

Water, the quality of which meets accepted standards as to its suitability for human consumption.

Pressure head

The pressure of a fluid expressed as the height of a column of the fluid with the pressure measured at its base.

Prestressed concrete

Concrete in which stresses are induced in reinforcing steel/cables, to a desired degree, to counteract the stresses resulting from external loads.


A method of prestressing in which the tendons are tensioned before the concrete is placed.

Prime cost sums

See Sums

Protecto Wrap

Top with an adhesive surface used as a secondary defence to water entry and accumulation

Purlin (includes tile batten)

A horizontal member laid to span across rafters or trusses and to which the roof cladding is attached.




Quantity surveyor

A professionally qualified person involved in estimating, tendering, preparing schedule of quantities and the financial administration of costs in construction.


Acute hollow sinking, groove or step, between a surface moulding and an adjoining flat surface.


The dressed corner stone in a random masonry wall.


The financial cost provided as a firm offer for contract work.




Racking (wracking)

Distortion of a frame or structure by overload.


A timber framing member normally parallel to the slope of the roof and providing support for sarking purlins or roof covering.

Rafter hip

A short rafter extending from the valley rafter to the ridge board or hip rafter or trimmer, or from the top plate to the hip rafter or trimmer.

Rafter, valley

A rafter which conforms to the slope of the intersection of two roof surfaces meeting in a valley and into which jack rafters are trimmed.

Reduced level (RL)

A level related to a nominated datum level.

Reflected plan

The plan of ceiling or the like, viewed from above as if reflected to the upper surface of a horizontal plane or section below the ceiling.

Reinforced concrete

Concrete containing steel reinforcement and designed and detailed so that the two material act together in resisting loads and forces.


Rods, bars or fabric, usually of steel, embedded in concrete for the purpose of resisting particular stresses.

Release agent

Substance usually applied to the form face to prevent adhesion of setting concrete to the form.

Relief vent

A vent pipe which is connected to a discharge stack below the lowest branch connection.


Mixture of sand and cement materials applied to an exterior surface.


Compound added to a composition to slow down a chemical or physical change, for example, to delay the setting of mortar or concrete.

Retention (liquid)

The amount of preservative in the form of liquid or dry compound remaining in the timber after treatment.


An amount held back in a contract until completion and maintenance periods.


The sides of a door or window opening or recess between the frame and the face of the wall.

Ribbon board (includes soffit plate)

A horizontal framing timber secured to or checked into the edges of studs and supporting floor

or ceiling joists or eaves bearers.


Highest part or apex of a roof.

Ridge board

The horizontal timber to which rafter of couple-close roofs are fixed at their upper ends.

Rigid Air Barrier

A board material and associated seals used to take up all external air pressure exerted within a cavity behind claddings.


The vertical distance through which anything rises such as the rise of a stair or the rise of a roof.


Vertical surface of a step.

Riser mains

A vertical pipe installed in a building for fire fighting purposes fitted with inlet connections at fire brigade access level and landing valves at specified points.

Rodding point

A removable cap in piping through which access may be made for cleaning and inspecting the drainage system.

Roof, flat

Any roof with a slope of less than 1:6.

Roof gabled

Pitched roof terminating at a vertical gable wall.

Roof, hipped

Pitched roof with the ends also pitched (tripped ends).

Roof, lean-to (skillion)

Building or extension of a building having a single-sloped roof the rafter of which lean against another building or other support.

Roof, mansard (French roof)

Double sloped pitched roof, rising steeply from the eaves and having its upper portion of flatter slope rising to a central ridge allowing greater access and use of the roof space.

Roof, saw-tooth

Roof where the light is admitted through one steep or vertical window from the top of which a sloping portion of the roof extends to a gutter at the foot of the next glazed face, and so on, the whole presenting a serrated profile.

Rot, brown

Type of decay caused by fungi which utilize mainly the cellulose and homo-cellulose fraction of the wood and leaving the lignin behind staining the timber brown.

Rough Order Estimate (Broadbrush)

An early approximate value placed upon work to be carried out.

Rough sawn

Surface condition of wood as it leaves the saw.


The common abbreviation for describing the values of both the thermal resistance and total thermal resistance of a material/s. Unit m2.oC/W. (NZBC).




Saddle Flashing

Flashing to the top of a parapet or cornice


The deflection or bending of a member between the points of support.


The living outer layers of the wood of a tree. It is generally lighter in colour than heartwood, although not always clearly differentiated from it. Often referred to as outerboard.


Boarding or sheet material secured to rafters, trusses or purlins and which may also serve as the ceiling lining.


Assembly or parts, being stile and rail members to contain glass, that moves on fittings within, from or across the light of a window. In sliding doors these are called panels.

Sash, double-hung

Two or more sashes which slide past each other in a vertical plane, and which are counterbalanced.

Sash, top-hung

Sash that is hinged on a top edge.

Scant cut timber

Cut under size.

Schedule (Bill) of quantities

A document that contains descriptions and measurements of all items of work required to carry out a given construction project.

Schedule of rates

A list of items giving brief identifying descriptions and the measured quantities of work included in a contract for the purpose of obtaining unit prices only.


A volcanic slag or clinker, dark in color in shades of maroon to dark grey, vesicular and usually of basic composition. It very commonly occurs as loose fragments, generally between 4 and 32 mm, alternatively the name can be used for the rough vesicular crust on individual lava flows.


A shaped turn bar or plaster finishing mould inserted at the junction of walls and ceilings.

Scotia (cavetto)

A concave moulding.

Screw jack

A length of heavy pipe with an adjusting screw fitted in one end and with a heel plate or bearing plate fitted at the other end. Used to support formwork.


Marking and shaping the end or edge of a piece of material to fit an adjoining surface.


Coarsely woven fabric or hemp or jute with an open weave.


Clear or pigmented liquid used on absorbent surfaces prior to painting, which when dried reduces the absorptive capacity of the surface, often known as ‘suction’. Also used to prevent bleeding or to guard against the softening action of solvents in a top coat.

Seasoned timber

Timber brought to a state of equilibrium moisture content.


Slow movement of water oozing from the ground, a wall or a bank.

Septic tank.

Tank used to dispose of sewage when a building is isolated from or cannot be connected to a sewerage system, the sewage being liquefied and purified by bacteria. The excess of overflowing liquid is known as the effluent.

Setting out

Defining the position of a structure on a site relative to site boundaries and other buildings.


The vertical downward movement of a structure after construction or due to an environmental event due to compression and deformation of the underlying soil.


  1. Partial or complete longitudinal separation between adjoining layers of wood due to cause other than drying and usually originating in the standing tree.
  2. A type of shingle used for roofing.

Shear wall

A wall designed to resist lateral forces parallel to the plane of the wall.


Material used as a backing to cladding such as rigid backing to plaster and also includes sarking or sheeting material that makes up the cladding itself.

Shim, structural

Thin metal slip used to fill a space between and/or to align steel members. For example shim packs may be used at the junction of a structural member and gusset plates.

Shingle, asphalt

Thin uniform-thickness pliable strip, made from bituminous impregnated felt or fibrous material. Surface finish is usually of uniform size mineral granules embedded in the bituminous surfacing.

Shingle, wooden

Thin sawn, tapered rectangular piece of timber for roof or wall cladding. Shingles are usually tapered along the grain in 400 mm, 450 mm and 600 mm lengths. Widths are random between 75 mm and 350 mm. The average width of the thickener end (bottom end, butt end) is 125 mm.


Form of lapped joint in which abutting boards have a rebate cut in each edge, the two rebates being on opposite faces. Such joints may be used horizontally or vertically, in sheathing or in lining. Vertical exterior shiplap joints usually require additional weather grooving.


Wall sheathing comprising strips or pieces of sheet material fixed horizontally in lapping courses.

Sill (cill)

The lowest horizontal member of a frame for a window or door.


Oblique, slanting.

Skillion roof

A pitched roof where the ceiling lining is either fixed to the rafters or parallel and close to the roof cladding. The roof can be mono-itch or may consist of more than one roof plane. These roofs often have rafters exposed below the ceiling.


Trim fixed on a wall at its junction with the floor.


Flashings at exterior mitred angles and butt joints of weatherboards.


Pit of large stones or similar material to dispose of surface water by soakage into the soil.

Socket outlet

Electrical connection point forming part of the fixed wiring which is designed to accept plugs to power appliances.


The lower face or under surface of anything, such as the underside of eaves of a roof.


General term for alloys used for joining metals such as electrical wires when melted and then, cooled to solid state.


To break away at the edges of stone or other masonry materials, through weathering, chemical action, or excess stresses and loadings.

Span, clear

Distance between the faces of walls, columns or piers supporting a beam or a truss.

Specification, building

A written document containing qualitative information describing the detail of a building project, generally to compliment the graphic information.


The plain end of a pipe that fits into the socket end of another pipe.


A course of bricks or blocks less than their ordinary thickness.


Open gutter attached to eaves.

Stachybotrys (SPP.)

A soft rot mould that will consume cellulose based products when a high relatively humidity exists. Can bear toxic substance that are a health risk.

Stack Bonded

System in which blocks or bricks are laid with continuous vertical joints. Not a true bond


Arranged in positions alternately on either side of a median line (for example, in zig-zag screwing or nailing).


Vertical strut or column usually of steel, vertical strut to a handrail.

Steel, high-tension

Steel having a higher tensile strength than mild steel. The increase in strengths is often accompanied by a reduction in ductility.

Steel, mild

The most commonly used steel for structural engineering work, generally in sheet, strip, tube and rolled sections. The yield stress is usually about 250 MPa. Mild steels are in various grades and are ductile, weldable steels.

Steel, stainless

A corrosion-resisting alloy steel of a wide variety of compositions, but always containing a high percentage of chromium.

Stiffener (web stiffener)

  1. Vertical side member of a sash other than an interlocker.
  2. A side member that supports the treads or rungs of a ladder. The terms ‘side rail’ and ‘stringer’ are often used synonymously.


Reinforcement used to resist shear and torsion in a structural member, consisting of L, U or rectangular shapes and located perpendicular to or at an angle to longitudinal reinforcement.

Stopped end

Square end termination of a component, such as the squared end on a spouting.


To fill blemishes in work to be painted, such as nail holes and cracks, to bring them to an even surface after the application of the first or priming coat in timber work, and prior to painting in plaster work.


  1. Metal plate or strip to secure a joint in framing or to the down framing to the concrete foundation.
  2. Batten secured to a concrete, brick or stone structure or to timber framing to provide fixing for an interior lining.

Striking plate

Plate, fixed to a door jamb, with one or more openings in which the bolt or bolts of a lock or latch engage.


Horizontal framing timber fixed to the side of a concrete or masonry wall to support/secure the ends of joists or rafters.


Solid cement plaster claddings applied on a background of galvanized mesh or lath over rigid or non-rigid backings fixed to timber or steel framing.


Vertical timber, forming part of a wall or partition on to which cladding may be fastened.

Subfloor brace

A bracing element below the lowest floor level.


Caving in or sinking of the ground.


A chamber which is installed in the drain and incorporates features to intercept and retain silt, gravel and other debris. (NZBC).

Sums (monetary allowances);

Contingency sums

Contingency sums are for items, the nature or extent of which cannot be defined otherwise in the contract documents. Such sums are wholly under the control of the architect, engineer or client’s representative administering the works and may be expended or deducted in part or in whole under his/her authority.

Prime cost sums (P.C.)

Prime cost is a specified adjustable sum for the purpose of including in a contract an amount for the supply of required materials or fitments of appropriate quality. (Usual examples, hardware and plumbing ware).

Provisional sums

Provisional sums are specified adjustable sums to be expended in whole or in part as directed by the architect, or clients representative/engineer administering the works, for sections of the contract which are not described fully in the documents, but for which necessary specifications and drawings may be prepared and separate tenders invited.

Surface treatment (timber preservative)

Application to wood of a preservative in liquid form, by brushing, spraying or dipping.





A continuous waterproof membrane applied to a surface to prevent the ingress or egress of water.


A steel element of group or elements such as wire, cable, bar or strand used in tension in a concrete member or structure to improve the strength and properties of concrete elements.

Terra-cotta (literally ‘baked earth’)

A hard unglazed ceramic usually clay of which decorative tiles and bricks and architectural decorations are made. Its colour varies from yellow to brownish red.


A rendering of cement and marble or chips of other hard material, used as a surfacing for concrete floors on which it is floated and finally polished with carborundum blocks and fine grit stones; this is also used to form facings for precast elements.

Test, smoke

Test sometimes applied to drains. The ends are lugged, dense smoke is pumped in and any escape indicating leakage can be observed.


Having the property of being softened by heating and hardened by cooling; this process is repeatable.


Automatic device to operate an indicator or a valve, switch or alarm when a predetermined temperature is reached.


A sill to an external door, or the floor under an internal door. (NZBC).

Tile, acoustic

Panels that absorb a high proportion of sound, made from material such as soft fibreboard or perforated plaster.

Tile, ceramic (fired clay tile)

Thins piece of baked or burnt clay, glazed or unglazed, flat or interlocking, to suit various building requirements.

Titanium dioxide (TiO2)

The principal white pigment used in the manufacture of paint, plastics, rubber and linoleum. A highly opaque non-poisonous pigment unaffected by acids and alkalis.

Toby Box

Surface box generally set flush with paving or other surface to cover the stop-cock or control valve of a water or gas supply.

Top Plate

A plate laced over the top ends of stubs.

Top Plate

The upper horizontal member of a timber frame.

Tower bolt

A bolt which slides in spaced rings or clips attached to a backing plate.


The toxic nature of moulds and bacteria on other building products.


Intermediate horizontal members fixed spanning between jambs, or between jambs and mullion or mullion and mullion of a window frame subdividing the window into lights.


A chamber which is installed in the drain and incorporates features to intercept and retain floatable or heavy (metal) debris.

Trap, grease

Large trap designed to prevent grease from entering and clogging drains. It is provided with means of extracting the collected grease.

Trap, gully (yard trap)

Receptacle to trap and drain where rain or waste water is collected before entering the drain.

Trap, P

Trap fitted close or seal off a fixture outlet in which the outlet ‘leg’ discharges horizontally.

Trap, S

Trap fitted close to a fixture outlet in which the outlet ‘leg’ discharges vertically downward.

Trimming stud

A stud located on the side of and under an opening.

Tyrolean finish

A splatter type of plaster coating usually applied by machine.




Ultimate strength design

A method of proportioning reinforced concrete members based on calculations of their ultimate strength. To ensure serviceability, consideration is also given to control of deflection and cracking under service loads.


The paint coat applied to a surface after priming and filling or after the preparation of a previously painted surface, and before the application of a finishing coat.


Supporting a building while rebuilding or extending the foundations or carrying out adjacent work below the foundation level.


A horizontal timber member laid underneath rafters, supporting the rafters at intermediate points along their length.





Internal or recessed angle in a roof between two intersecting roof slopes. The opposite of Hip.

Valve, pressure reducing

Automatically reduces system pressure to a determined value on the downstream side of the valve.

Valve, pressure relief

Automatically prevents system pressure rising above a predetermined value by allowing intermittent discharge to atmosphere.

Valve, stop, isolating value or stop-cock

Any valve installed for the purpose of isolating part of a water system.

Valve, temperature relief

Fitted to a hot water cylinder to relieve pressure created by thermal expansion when the temperature of the water exceeds a predetermined level in the event of failure of the normal operating controls.

Vapour barrier

Sheet material or coating allowing a very low or no water-vapour transmission, and used to minimize water-vapour penetrating in buildings. (Vapour barriers are sometimes referred to as damp-proof membranes).


The process of changing or circulating the air in an enclosed space by natural or mechanical means.


A roof space extending from a building.


Mineral of the mica group with a property of expanding many times under heat. Expanded (or exfoliated) vermiculite is used as a lightweight aggregate and in thermal insulation.


An entrance space intended to provide an antechamber immediately within the external doors of a building.


Internal resistance to flow possessed by a liquid.


Glass-like in luster, colour, brittleness or composition.


Space left in a wall as for a window or door. Any utilized space in a building or structure.




Wall bracing element

A section of wall above the ground floor level that performs a bracing function.


The presence of the original underbark surface with or without bark on any face or edge of a piece of timber.


Any variation from a net surface. It may consist of cup, bow, crook, twist or any combination of these.


Noise and shock occurring in water pipes due to a sudden interruption of the flow of water caused, for example, by the rapid closure of a valve or by pump start or stoppage.

Water, hard

Water having magnesium, calcium or other salts in solution which make lathering of soap difficult.

Water heater, low pressure

A water heater designed to work under a pressure not exceeding 12m head of water (120 kPa).

Water heater, mains pressure

A water heater designed to work at pressures exceeding 12m head of water (120 kPa).

Water paint

Any paint in which the greater portion of the vehicle is water.

Water seal

The depth of water that can be retained in a water trap. (NZBC).

Water trap

A fitting designed to prevent foul air escaping from the plumbing system or foul water drainage system and entering a building. (NZBC).

Watt (W)

The unit of electric power signifying energy . A commonly used multiple is the kilowatt (kW) (1000 watts).

Weather bar

A strip of corrosion-resistant metal or material fitted into a groove in the underside of a wooden sill and fitting into a corresponding groove in a stone sill, or bedded into a concrete sill. Usually set in mastic.

Weather groove

Groove in two adjacent surfaces of a sash or door and the frame to create a ~ leak and prevent the passage of liquid water.

Weatherboarding, beveled back

Form of weatherboard which has a relatively wide bevel formed on the back allowing the bevel to lie net on the plane of the studs and providing the necessary slope to cover an upper part of the weatherboard below.

Weatherboarding, rusticated

The moulding of a channel on a board, the upper portion of which is covered by a corresponding rebate in the board above.


Small holes in a retaining wall or abutment, which allow drainage to prevent the accumulation of water behind the structure.

Wet riser

Same as for riser mains whereby the vertical pipe is permanently charged with water from a pressurized supply

Window, dormer

Projection through a sloping roof to allow a means of lighting an attic.

Wire dog

Galvanised or stainless steel wire, U or Z shaped nail, spiked at each end. Used for fixing together timber placed at 90o to each other to resist uplift.










Zinc-rich paint or primer

Anti-corrosive paint or primer for iron and steel incorporating zinc dust to give cathodic protection. Zinc-rich paint may have an organic or inorganic vehicle.