West Berkshire Council

Measuring Gross Internal Area for the Community Infrastructure Levy

How GIA is calculated

A development where the gross internal area of new build is over 100 square metres and all new dwellings then it is deemed to be liable for CIL.

The floor area proposed to be lost by demolition may be calculated to reduce the CIL liability. In order for the liability to be reduced, the existing floorspace must satisfy the requirements of regulation 40.

The guidance used when measuring to determine CIL is the RICS Code of Measuring Practice. This states that: "gross internal area is the area of a building measured to the internal face of the perimeter walls at each floor level."

When calculating gross internal area, we include:

  • internal walls
    • including party walls in the case of adjoining new houses
    • walls between main living spaces and integral garages
  • floor space into doorways
  • areas exposed by removing walls
  • areas under 1.5m in height
  • areas underneath stairs
  • garages
  • car ports with two or more walls
  • undercroft parking
  • useable space with permanent access (eg loft conversions)
  • balconies and porches enclosed on three sides

Who To Contact

For queries about Community Infrastructure Levy, S106 Planning Obligations and payment of Developer Contributions

01635 519111