Carpet, built-up, saleable: reading an area statement

Two apartments described as "3,000 square feet" can differ by a third in usable space. The difference is almost always the basis on which the area has been measured.

Before comparing homes, offices or estates, it is worth knowing which figure you are looking at — and asking for the others.

Carpet area

Carpet area is the usable floor area within the walls of a unit. It is generally the most useful figure for comparing how much space you will actually live or work in.

Built-up area

Built-up area typically adds the thickness of walls and certain balconies or terraces to the carpet area. Definitions vary, so always ask what has been included.

Saleable and leasable area

Saleable (or super built-up) area, and leasable area in commercial buildings, add a share of common spaces such as lobbies, corridors and amenities. These figures are useful for understanding how charges are calculated but less useful for comparing usable space.

Questions to ask

When reviewing any property, we suggest asking:

• 01Which basis does this figure use?
• 02What is the carpet area, separately stated?
• 03Are terraces or balconies included, and on what basis?
• 04For land: what unit was used in the original documents?

On our property pages we state the basis next to every area figure, and we do not combine incompatible measures. Where a figure is approximate, we say so.