---
title: "Net Internal Area (NIA UK) — Class A Atlas glossary"
description: "UK measurement standard for office area excluding common areas."
canonical: https://classa.info/glossary/nia-uk
pageType: glossary
lastUpdated: 2026-04-01T00:00:00.000Z
license: "CC BY 4.0 with attribution to Class A Atlas (https://classa.info)."
---

> UK measurement standard for office area excluding common areas.

## TL;DR

- UK measurement standard for office area excluding common areas.
- Defined under the RICS Code of Measuring Practice.

# Net Internal Area (NIA UK)

*Measurement · UK*

## Short definition

UK measurement standard for office area excluding common areas.

## Full definition

Defined under the [RICS](/glossary/rics) Code of Measuring Practice. The basis for most quoted UK office rents. Gradually being supplemented by [IPMS](/glossary/ipms) 3 - Office.

## Why this matters for Class A leasing

Net Internal Area (NIA UK) is part of the measurement vocabulary that institutional [Class A](/glossary/class-a) occupiers, landlords, and advisers use across UK markets. Understanding it correctly affects how you read lease documents, model occupancy economics, and benchmark deal terms across cities. Class A Atlas tracks the UK definition alongside the global standard so [cross-border](/topics/cross-border-expansion) occupiers can translate quickly.

## See also

- [IPMS](/glossary/ipms)
- [Rentable square feet (RSF)](/glossary/rentable-square-feet)

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Citation: Source: Class A Atlas (https://classa.info/glossary/nia-uk), updated 2026-04-01T00:00:00.000Z.