Floor area measurement: GIA, NIA and IPMS
Gross and net internal areas measured to the RICS Code of Measuring Practice or IPMS, with area schedules and marked-up plans for valuation, leasing, rating and sales.
Why measured areas matter
Floor areas drive rents, valuations, service charges, business rates and development costs. Small differences across a building add up quickly, so the figures need to come from measured geometry and a clearly stated basis.
Measurement standards
We measure to the RICS Code of Measuring Practice for GIA, NIA and GEA, and to the International Property Measurement Standards (IPMS) where instructed. Every schedule states the basis used, so anyone checking the figures can follow how they were derived.
For new-build apartment schemes
For as-built sales areas on residential developments, see net sales area verification, which compares measured areas with your design schedule unit by unit.
How it works
Agree the basis
Confirm which measurement basis is required and how the building is split into units or tenancies.
Survey
The building is surveyed by laser scan and total station so areas come from measured geometry, not old drawings.
Schedule and plans
You receive the area schedule and marked-up plans, with the basis stated so the figures are auditable.
Who we work with
Agents and valuers
Reliable areas for valuation, marketing and rent reviews.
Landlords and asset managers
Consistent area records across a portfolio.
Developers
Measured GIA for cost plans and CIL, and NIA for lettings.
What clients say
Read our reviews on Google★★★★★
Having worked with THS for several years now, each project is treated with high professionalism every time. We would highly recommend their team.
★★★★★
I was impressed by THS Concepts topographical survey services' professionalism and accuracy. They were efficient and reasonably priced. I highly recommend them.
★★★★★
We recently approached THS Concepts to carry out a level survey of the screed to the ground floor of a large residential property we were Project Managing. The property was undergoing extensions and refurbishment work. We had a tight timescale to receive the information, and THS Concepts delivered quickly and efficiently to meet our deadline. This is the second time we have used them and would highly recommend.
Area measurement (NIA, GIA): common questions
What is the difference between GIA and NIA?
Gross internal area is the whole area inside the external walls at each floor. Net internal area is the usable area within that, excluding items such as stairs, lifts, plant rooms, toilets and structural walls. Our guide to NIA and GIA explains the rules with diagrams.
Do you measure to IPMS?
Yes, where the instruction requires it. We state the basis on every schedule so it is clear which standard was used.
Can you measure from existing drawings?
Areas taken from old drawings often differ from what was built. We measure on site so the figures can be relied on.
Related services
- Building height surveys
Height and storey measurement for the Building Safety Act.
Tell us about your site
Send a location, a rough brief and your deadline. We reply with a fixed quote within 24 hours.