PCATP ALE key terms

The minimum horizontal distance a building must be kept from a property line, street edge, or other boundary, fixed by zoning rules to protect light, air, privacy, and fire access.

The ratio of a building's total covered floor area to the area of the plot on which it stands. Regulators use it to cap development bulk independently of plot size.

The percentage of a plot that may be covered by a building footprint when viewed from above. It controls open space and daylight at ground level rather than total built volume.

A line drawn on a development plan beyond which no structure may project toward the street. It may sit behind the property line and differs from the setback in being a fixed control line.

The strip of land reserved for a road, footpath, or utility corridor, measured between property lines. Its width sets the space available for carriageway, verges, and services.

A legal right to use another person's land for a specific limited purpose, such as drainage, access, or running services, without owning it. It binds later owners of the land.

The registered legal document proving ownership of land or property and recording the owner's name and the rights and encumbrances attached to it. It is the basis for verifying ownership before purchase.

The official updating of land revenue or ownership records after a sale, inheritance, or gift so that the register names the current owner. It transfers record entries, not title itself.

The division of land by a planning authority into districts with permitted uses, such as residential, commercial, industrial, or agricultural, together with density and height controls. It directs growth and separates incompatible activities.

A long-range statutory or policy document that sets the broad pattern of land use, transport, housing, and services for a town over roughly twenty years, guiding detailed local plans and development approvals.

The planned redevelopment or rehabilitation of deteriorated urban areas through clearance, upgrading, or adaptive reuse, usually combined with improved infrastructure and relocation of affected residents.

Giving a new use to an existing building while retaining its significant structure or character, such as converting a warehouse into housing. It reduces demolition waste and often preserves heritage value.

The total greenhouse gas emissions associated with extracting, manufacturing, transporting, installing, maintaining, and disposing of building materials over a building's life. It excludes emissions from operating the building.

A structured method of estimating environmental impacts of a building or material across its whole life, from raw material extraction through use to end of life, usually reported per functional unit.

A measure of how readily heat passes through a building element, expressed in watts per square metre per kelvin. Lower values mean better insulation and are capped by energy codes.

Design that uses orientation, shading, mass, insulation, and natural ventilation to keep indoor conditions comfortable with minimal mechanical energy. It is decided early, since later changes are costly.

The ratio of illuminance at a point indoors to the simultaneous illuminance on an unobstructed outdoor horizontal surface, expressed as a percentage under overcast sky conditions. It indicates how well a space is naturally lit.

Visual discomfort or loss of detail caused by luminance within the field of view far brighter than the surroundings, or by excessive contrast. It is controlled by shading, diffusing, and limiting brightness ratios.

The ratio of useful heating or cooling delivered by a heat pump or chiller to the energy it consumes, measured at stated conditions. Higher values indicate more efficient equipment.

The collection, storage, and use of rainwater from roofs or other surfaces for non-potable needs or groundwater recharge, reducing demand on mains supply and stormwater runoff.

The period, in minutes or hours, for which a building element resists fire exposure while retaining stability, integrity, and insulation, as established by standard fire testing. It governs compartmentation and escape protection.

The subdivision of a building into fire-tight zones by rated walls, floors, and doors so that fire and smoke are held in the zone of origin long enough for occupants to escape.

The continuous protected route from any point in a building to a place of safety outside, made up of exit access, exits, and discharge, sized for the occupant load it serves.

The number of people a floor, room, or building is expected to hold, calculated from floor area and use type. It sets exit widths, stair numbers, and sanitary fixture counts.

The required number of water closets, washbasins, and other fittings per number of occupants or floor area for a given building use, set by building bye-laws to ensure adequate provision.

A vertical pipe carrying soil or waste water down through a building to the drainage system, usually vented to maintain air pressure and protect trap seals.

A field test in which fresh concrete placed in a standard cone is allowed to settle, and the drop of the top is measured to indicate workability and consistency before placing.

The mass of water divided by the mass of cement in a concrete mix. Lowering it raises strength and durability but reduces workability, so it is balanced against admixtures.

A laboratory compression test on standard concrete cubes cured for set periods, usually 7 and 28 days, to confirm that the mix achieves its specified characteristic strength.

The internal turning effect at a section of a beam or slab caused by loads acting at a distance, producing tension on one face and compression on the other. It governs reinforcement placement.

The internal force acting across a section of a structural member that tends to slide one part past another. It produces diagonal tension, resisted by stirrups or shear reinforcement.

The distance between the supports of a beam or slab used in structural calculations, taken between centre lines of supports or clear span plus effective depth, whichever is smaller.

An itemized schedule listing measured quantities of work with descriptions, prepared from drawings so that tenderers price the same scope on a common basis for comparison.

A published set of rules for how building work is measured and described, such as which deductions apply to openings, so that quantities in a bill are consistent and checkable.

A written instruction issued under a contract authorizing a change to the scope, quantity, or timing of work, with its cost and time effects valued under the contract's variation provisions.

A percentage withheld from interim payments and held by the employer as security for defects, released in stages, commonly half at practical completion and the balance after the defects liability period.

A stated period after practical completion during which the contractor must return and rectify defects notified by the employer at no extra cost, before final payment and release of retention.

The stage at which the works are substantially finished and fit for their intended use, apart from minor items, triggering handover, the defects period, and release of part retention.

Cover protecting an architect against claims for financial loss arising from negligent design, advice, or certification, usually written on a claims-made basis with a stated retroactive date.

A situation where a professional's personal, financial, or other interest could improperly influence judgement on a client's project, requiring disclosure and often withdrawal from the decision.

The legal obligation of a professional to exercise reasonable skill and care toward those who may foreseeably be harmed by the work, including clients and, in some cases, later users.