D11 and D12 of the EMS record collect information on the GIA and NIA of the institution.
What is GIA?
Gross internal area (GIA) is the total area of buildings owned, occupied
or maintained by the HEI measured to the internal face of
the perimeter walls at each floor level (i.e. the footprint of the
building excluding the width of the outside walls). It includes areas
occupied by internal walls and partitions.
What is NIA?
Net Internal Area (NIA) 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.
- Teaching and research rooms
- Built-in units, cupboards etc. occupying usable area
- Academic stores
- Changing rooms and showers (e.g within or as part of clean rooms, catering facilitie, sports facilities)
- Porters' offices and kiosks
- First aid rooms
- Staff common rooms
- Internal partition walls (e.g. fixed walls, de-mountable re-movable screens)
- Ramps of lightweight construction to false floors
- A floor area which contains a ventilation/heating grille
- Area occupired by skirting and perimeter trunking
- Areas severed 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 ther are several
functions using the area, such as meeting space, reception or cafe.
- Accommodation on NHS sites which is maintained or paid for.
does not include those parts of buildings which enable them to
function, such as corridors. These are classified as balance areas. (See What are balance areas? below).
Approaches for defining NIA
There are two alternative approaches for the return of data on net internal area (NIA):
1. NIA RICS basis
- NIA RICS (Royal Institution of Chartered Surveyors) basis
- NIA room area
The NIA RICS definitions are contained in the 'Code of Measuring
Practice: A Guide for Property Professionals' (Sixth Edition), published
by the RICS. This method involves the measurement of the internal room
area part way into the width of internal walls and partitions.
This is the preferred method of measurement and is demonstrated by the left-hand room in the diagram below.
2. NIA room area
This method involves the measurement of the internal room area less the
widith of internal walls and partitions.
This is the less preferred
method of measurement
and is demonstrated by the right-hand room in the diagram below.
Uplifting NIA room area
HESA captures detail of the NIA measurement method used in D13. Where
the NIA room area basis is used HESA will apply a 6% uplift to the NIA
measurements returned in D12. Application of this uplift is necessary to
ensure that the EMS ratios use a consistent value of internal area
across the sector.
What are balance areas?
Balance area is the floor area provided as part of the GIA to enable the building to function.
Balance area should be excluded from the NIA calculations.
The following are examples of balance areas:
and other circulation areas
of a permanent nature (e.g. fire corridors, smoke lobbies, etc.)
open-sided balconies or similar
structural walls, walls
enclosing excluded areas, columns, piers, chimney breasts, vertical
ducts and other projections
and stairwells (and voids
lobbies (where the function is
solely or primarily for entry/circulation)
(where the function is solely or
primarily for entry/circulation)
with clear height above, measured
at base level only (where the function is solely or primarily for
lift lobbies, permanent lift
rooms, liftwells and lifts (and voids over)
and toilet lobbies
cupboards (as defined in the
- 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.
air-conditioning, heating or cooling apparatus (as defined in the RICS
Therefore in the diagram below the balance area is that which is not
contained within the red box. The area contained within the red box is
eligible for inclusion within NIA. The area lying outside of the red box
is excluded, i.e. the corridor and lavatory.