Is my building a higher-risk building?

Under the Building Safety Act 2022, a higher-risk building in occupation in England is one that:

• is at least 18 metres in height or has at least seven storeys, and
• contains at least two residential units.

If your building meets both parts of the test, it must be registered with the Building Safety Regulator and the Accountable Persons take on extra duties, including the safety case.

How height is measured

Height is measured from the ground level at the lowest side of the building to the top of the floor surface of the top storey. Roof-top plant rooms and storeys that only contain plant are ignored. On sloping sites, use the lowest adjacent ground level.

How storeys are counted

Count storeys above ground level. Basements are not counted. Mezzanines count as a storey only if their floor area is at least half the floor area of the largest storey that is not a basement. Roof-top plant areas and storeys consisting only of plant rooms are ignored.

What counts as a residential unit?

Flats and other dwellings count, as do rooms in student accommodation and similar residential settings. Buildings that are wholly hotels, hospitals, care homes, secure residential institutions or military premises are excluded from the occupation-phase regime, although hospitals and care homes are included during design and construction.

Mixed-use buildings

A building with offices or shops on the lower floors and flats above can still be a higher-risk building if the building as a whole meets the height or storey test and has at least two residential units.

Use our checker

The checker on this page asks four questions and tells you whether your building is likely to fall inside the regime. It is a starting point, not legal advice. If the answer is close, get the building measured.

What to do if it is in scope

• Make sure it is registered with the Building Safety Regulator.
• Check the key building information submitted with the registration.
• Identify the Principal Accountable Person and any other Accountable Persons.
• Start assembling the safety case evidence.
• Put a resident engagement strategy and a mandatory occurrence reporting system in place.

What if it is just under the threshold?

Buildings below 18 metres and seven storeys are not higher-risk buildings, but they are still covered by the Fire Safety Order and, in England, by the Fire Safety (England) Regulations 2022. Buildings with storeys above 11 metres have duties such as fire door checks and secure information boxes. Good evidence and record-keeping are just as valuable there.