Last edited 03 Jun 2016

Gross floor area GFA

The area of a building can be measured in a number of different ways, and it is very important to be clear about which measure is being used, for example in property sales, planning applications, building regulations applications, lease negotiations, rating valuations and so on.

The term 'gross floor area' (GFA) is a very confusing one that has different meanings around the world, and even within some countries.

Part L of the UK building regulations suggest that it is equivalent to the total useful floor area (TUFA), which is the ' area of all enclosed spaces measured to the internal face of the external walls.'

However, in may countries gross floor area is taken to be the total enclosed space including the external walls.

For this reason it is clearer to use the terms:

  • Gross internal area: The enclosed area of a building within the external walls taking each floor into account but excluding the thickness of the external walls.
  • Gross external area: The whole area of the building, including external walls.

Precise definitions for the accurate measurement of buildings are set out by the Royal Institution of Chartered Surveyors in the RICS Code of Measuring Practice.

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