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Estates Management record 2013/14 - Net Internal Area - D12NetInternalArea

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Estates Management record 2013/14

Fields common to all countries

Net Internal Area - D12

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Short nameNetInternalArea

The fields in this entity contain data about Net Internal Area (NIA).

Applicable toEngland Northern Ireland Scotland Wales

All higher education providers (HEPs).


There are two alternative approaches for the return of data on NIA:

The NIA RICS definitions are contained in the 'Code of Measuring Practice: A Guide for Property Professionals', published by the RICS.

Room area is NIA less the width of internal walls and partitions. Information is required for the same categories of space as NIA, with the same definitions applying apart from the measurement of space.

HEPs should return data in the form that is most straightforward for them. However the NIA RICS definitions are preferred.


Net Internal Area is the usable area within a building measured to the internal face of the perimeter walls at each floor level. NIA covers all areas which are used for a specific purpose. It does not include those parts of buildings which enable them to function i.e. balance areas defined below.


  • teaching and research rooms,
  • offices,
  • kitchens,
  • workshops,
  • built-in units, cupboards etc. occupying the useable area,
  • stores,
  • academic stores,
  • changing rooms and showers (e.g. within or as part of clean rooms, catering facilities, sports facilities),
  • porters' offices and kiosks,
  • first aid rooms,
  • staff common rooms,
  • internal partition walls (e.g. fixed walls, de-mountable re-moveable screens),
  • ramps of lightweight construction to false floors,
  • a floor area which contains a ventilation/heating grill,
  • area occupied by skirting and perimeter trunking,
  • areas served by internal non-structural walls, de-mountable partitions (whether or not permanent) etc. where the purpose of the division is partition of use (and not support) provided the area beyond is not used in common (by more than one occupier),
  • pavement vaults,
  • notional lift lobby and similar areas, where there are several functions using the area, such as meeting space, reception, or cafe,
  • accomodation on NHS sites which is maintained or paid for,

It does not include those parts of buildings which enable them to function, such as corridors. These are classified as balance areas.

Balance area

Balance areas include the floor area planned or provided as part of the Gross Internal Area to enable the building to function, such as:

  • corridors and other circulation areas of a permanent nature (e.g. fire corridors, smoke lobbies etc.),
  • internal open-sided balconies or similar,
  • internal structural walls, walls enclosing excluded areas, columns, piers, chimney berasts, vertical ducts, and other projections,
  • stairways and stairwells (and voids over),
  • entrance lobbies (where the function is solely or primarily for entry/circulation),
  • foyers (where the function is solely or primarily for entry/circulation),
  • atria with clear height above, measured at base level only (where the function is solely or primarily for entry/circulation),
  • lifts,
  • permanent lift lobbies, permanent lift rooms, liftwells, and lifts (and voids over),
  • lavatories and toilet lobbies,
  • cloakrooms,
  • cleaners' stores,
  • cleaners' cupboards (as defined in the RICS definition),
  • covered areas (e.g. plant rooms, tank rooms, fuel stores which are housed in a structure of a permanent nature, whether or not above main-roof level,
  • loading bays,
  • ducts,
  • permanent and continuous air-conditioning, heating, or cooling apparatus (as defined in the RICS definition),
  • boiler houses,
  • calorifier chambers,
  • fuel stores.

Space otherwise considered as balance areas, such as foyers, may only be included in NIA where it meets the appropriate definition.


There are a number of items that should be excluded from space measurement, such as:

  • accommodation on NHS sites which is neither maintained nor paid for,
  • areas under the control of service or other external authorities including meter cupboards and statutory service supply points (as defined under the RICS definition),
  • areas with a headroom of less than 1.5m (as defined under the RICS definition),
  • commercial space i.e. space not used for HEP purposes.

Breakdown of NIA space

Where space is used for dual purposes, an attribution on the basis outlined under heading Method of space apportionment should be used. This will apply in particular to data returns under headings Teaching total and Research total.

In addition, any space such as storage space that may be attributable to either the 'office' or 'core' element of teaching or research, should be assigned to either of these categories on the basis of their actual use. Thus, if a storage room opens into a teaching office and is used for storing student records, then it should be assigned to teaching office space. The same method must be used for all space allocation.

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