The area of a building can be measured in a number of different ways:

  • Gross external area (GEA).
  • Gross internal area (GIA).
  • Net internal area (NIA)

It is very important when describing the area of a building 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 net internal area (NIA) of a building is the usable area measured to the internal finish of the perimeter or party walls, ignoring skirting boards, at each floor level. Net internal area covers all of those areas that can be used for a particular purpose.

The UK government’s Valuation Office Agency (VOA) Code of measuring practice: definitions for rating purposes suggests that Net Internal Area includes:

  • Kitchens.
  • Any built in cupboards or units that occupy usable areas.
  • Perimeter skirting boards, mouldings and trunking.
  • Open circulation areas such as atria, corridors and entrance halls.
  • Partition walls and other dividing elements.
  • Net internal area excludes:

Internal structural walls.

  • Walls (whether structural or not) enclosing excluded areas.
  • Piers, columns, chimney breasts, ducts and other projections.
  • Cleaner’s cupboards.
  • Lifts, lift rooms, lift wells.
  • Stairwells and landings.
  • Stairwells, entrance halls, atria, landings and balconies used in common or for the purpose of essential access.
  • Corridors and other circulation areas used in common with other occupiers or of a permanent essential nature.
  • Boiler rooms, fuel stores, plant rooms and tank rooms other than those of a trade process nature.
  • Car parking areas.
  • Spaces occupied by cooling and heating equipment, air conditioning systems and ducting which renders the space substantially unusable.
  • Areas with a headroom of less than 1.5m.
  • Toilets and associated lobbies, unless additional toilets have been installed.
  • Areas under the control of service or other external authorities.

It suggests that, ‘essential access’ ‘…will not include reception areas or areas capable of use and situated within entrance halls, atria and landings etc.’

In relation to the term ‘permanent essential nature’ it suggests that, ‘apart from areas used in common with other occupiers, corridors excluded from NIA are those of a permanent essential nature, i.e. internal corridors between structural walls (usually found in older buildings). Fire corridors and smoke lobbies which are defined by non-structural walls – but only where they are permanent and essential to any prospective tenant of the property and do not merely serve the needs of the actual occupier. If the latter, they should be included.’

RICS Guidance Note, A guide for Property Professionals, 6th Edition Code of measuring practice 2007, is in general agreement with the Valuation Office Agency definition, of net internal area..

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About Towers Richardson

Towers Richardson are a professional CAD and surveying practise that specialise in producing Land Registry Compliant Plans and other floor plans. We have been producing Title Plans and Lease Plans since 1994 with a 100% success rate. We work closely with solicitors to make sure every detail is correct and compliant with the Land Registry.

Working from Yorkshire we are centrally located to travel throughout the UK to meet the needs of our current and future clients.

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We offer a complete bespoke service. Some of the work we have completed include, GIA & NIA Floor Plans, ITZA Floor Plans, HMO Floor Plans, Site Plans, 3D Visuals and Renderings, CAD Drafting, Fire Route Plans and elevation drawings.

If there is something that we could possibly help then please get in touch for a quote.

Michael
Michael
09/10/2021
Exceptional service from Scott Towers. All plans drawn up accurately and speedily from information provided by email. Subsequent amended plans drawn up at no additional cost. I cannot recommend Towers Richardson highly enough. Please do not hesitate to use this service.
Tetyana
Tetyana
13/09/2021
Fantastic service! Asked for a quote Thursday evening after hours and already had my floor plans inboxed mid Saturday. There was some alterations needed (my fault), which were done within a few hours. Can't ask for better work! Highly recommended.
Luke Brettingham
Luke Brettingham
07/09/2021
Quick, communicative, and cost-effective. Very happy customer
Natalie  Maunder
Natalie Maunder
07/09/2021
Great service excellent job
Terry Jackson
Terry Jackson
02/09/2021
Absolutely first class service, Scott was extremely helpful and dealt with queries and revisions quickly and efficiently. I would really recommend his service. Terry
JulieAnn Wales
JulieAnn Wales
02/09/2021
Professional, Helpful and Swift Service - Highly Recommend From the first call, Scott at Tower Richardson was hugely helpful in drawing up a plan to register a land purchase for me. I am in Scotland and was not sure if the mapping up here would be any different legally to ensure Compliance. Scott happily went off to research this for me. There were several tweaks and changes to the plan along the way and this was all done very swiftly and at a very reasonable price (compared to earlier architect plans I had drawn up). I would use Towers Richardson again in a heartbeat!
E Coomber
E Coomber
31/08/2021
Fantastic service. Easy to contact and communicate with at all times. Our plan was produced within 24hours, despite it being a Bank Holiday weekend! The speed, quality and friendliness of the service was impressive (and very welcomed while trying to navigate through a very convoluted and confusing property sale!)
Alison Louise Westbrook
Alison Louise Westbrook
15/07/2021
Excellent service, very professional and attentive to customers needs. Very pleased with the plans they drew up for me.
Tom Wycherley
Tom Wycherley
06/07/2021
Excellent Service; requested a quote at 21.00 yesterday, accepted the quote at 22.00 and received the lease plan at 10.00am this morning - what more can you ask for!
Janet Roebuck
Janet Roebuck
02/07/2021
Towers Richardson - Highly recommended I would highly recommend Towers Richardson (Scott). He was suportive and very helpful. The service was quick, (within 12 hours) nothing was too much trouble and was very resonably priced. Thank you very much.