What is a higher-risk building?

In short: For the in-occupation regime, a higher-risk building (HRB) is a building with at least two residential units that is at least 18 metres tall or has at least 7 storeys. A building only needs to meet one of the height or storey thresholds, not both.

The test

A building is in scope if it contains two or more residential units and reaches either threshold:

• 18 metres or more in height, measured from ground level to the floor of the top occupied storey; or
• 7 storeys or more.

Meeting either one is enough. Some buildings meet both, but that is not required.

What is included and excluded

The threshold is about residential occupation. In the occupation phase the building must contain at least two residential units. Certain building types - such as secure residential institutions, hospitals and care homes - are treated differently and are generally outside the occupation regime, even where they meet the height test.

Why it matters

If your building is an HRB, the duties under the Building Safety Act 2022 and the regulations made under it apply. The principal accountable person must register the building with the Building Safety Regulator, keep the golden thread of information, assess the building safety risks and prepare a safety case report. Operating an occupied HRB that is not registered is a criminal offence.

How CTS helps

CTS confirms whether your buildings are in scope, then helps you achieve and maintain compliance - registration, golden thread, inspections and the safety case - recorded on the CTS BuildSafe platform.

General information, not legal advice. Reviewed by the CTS building safety team.