Building area (BA)

See: Gross floor area; Fully enclosed covered area; Unenclosed covered area; Gross lettable area; Net lettable area; Net occupiable area; Usable floor area.

Common areas

Those areas within a building or tenancy not leased to a particular tenant, but which are available for the use of all tenants and usually of members of the public.

Common Use Areas

Floored areas in the building used for circulation and standard facilities provided for the common use of occupiers, tenants and/or public such as lobbies and foyers to entrances, stairways and lifts, landings and fire escapes, verandahs and balconies, corridors and passages, toilet and rest room areas, cloak and locker areas, cleaner's rooms including stores and cupboards, tea making and similar amenities areas. (SPAM)

Fully enclosed covered area (FECA)

The sum of all fully enclosed and covered building areas at all floor levels, including: basements (except unexcavated portions), garages, floored roof spaces and attics, penthouses, enclosed porches and attached enclosed covered ways, equipment rooms, lift shafts, vertical ducts, staircases and any other fully enclosed spaces and useable areas of the building. The FECA is computed by measuring from the normal inside face of exterior walls, ignoring any projections such as plinths, columns or piers. It excludes open courts, light wells, connecting or isolated covered ways, and net open areas of upper portions of rooms, lobbies, halls, interstitial spaces etc which extend through the story being computed.

Gross building area (GBA)

See: Gross floor area.

Gross floor area (GFA)

Usually, the sum of the fully enclosed covered floor area and the unenclosed covered floor area of a building at all floor levels. Some commercial and public authorities use variants of this definition. See also: Building area.

Gross lettable area (GLA)

Generally, the floor space contained within a tenancy at each floor level measured from the outside of main faces of external walls and, where applicable, the centre lines of internal inter-tenancy, partition and common area walls, but excluding features such as balconies and verandahs and, if there are two of more occupiers or tenants, excluding common use areas, service areas, and non-exclusive public spaces and thoroughfares. In the case of retail tenancy areas such as shops, measurements are often made from the internal finished surface of external building walls, service passage walls, etc. (Some commercial and public authorities use variants of this definition.)

Net lettable area (NLA)

The area for which a tenant could be charged for occupancy under a lease. Generally, it is the floor space contained within a tenancy at each floor level measured from the internal finished surfaces of permanent external walls and permanent internal walls but excluding features such as balconies and verandahs, common use areas, areas less than 1.5 m in height, service areas, and public spaces and thoroughfares. (Some commercial and public authorities use variants of this definition.)

Net occupiable area (NOA)

The net lettable area less any primary circulation space not already taken into account. For non-commercial facilities see: Usable floor area.

Net usable area (NUA)

See net occupiable area.

Non-Habitable Area

Internal columns and other structural supports, internal walls and permanent partitions, lift shafts, service ducts and the like. (SPAM)

Room Area

The room area is the area of the room, measured at floor level from the general inside face of partitioning walls, external walls or curtain glazing. (SPAM)

Service Area

All areas set aside for building plant and associated services (such as mechanical plant and equipment rooms, electrical equipment and switch rooms, tank rooms, lift motor rooms, meter cupboards, telecommunication switch rooms, refuse collection area) and facilities for the use of occupants, tenants and/or the public (such as loading bays, internal car-parking areas including their access ways).

Unenclosed covered area (UCA)

The sum of all unenclosed covered areas at all building floor levels, including roofed balconies, open verandahs, porches and porticos, attached open covered ways alongside the building(s), useable space under the building(s), unenclosed access galleries (including ground floor) and any other trafficable covered areas of the building which are not totally enclosed by full weight walls. The UCA is computed by measuring from the inside face of any enclosing walls, balustrades or supports, but excludes connecting or isolated covered ways, and eaves, overhangs, sun shading, or awnings unless they relate to clearly defined trafficable covered areas.

Usable floor area (UFA)

The 'Fully enclosed covered area' of a building or a floor less 'Common use areas', 'Service areas' and 'Non-habitable areas'. See also: Fully enclosed covered area; Common use area; Non-habitable area; Net occupiable area.

Area Definitions Diagram

Click here to download the Area Definitions Diagram (pdf - 162KB)