What is a higher-risk building?

The Building Safety Act 2022 created a stricter regime for the buildings where a fire would put most people at risk. If you own or manage one of them, you have duties that go beyond the fire risk assessment, and passive fire protection is at the centre of most of them.

The test, step by step

The government’s guidance for buildings in occupation sets out a two-part test from section 65 of the Act. A building is higher-risk if it meets both:

1. Height or storeys. It is at least 18 metres tall, or it has at least 7 storeys. Either is enough.
2. Residential units. It contains at least 2 residential units.

Measuring height

Height is measured from ground level to the floor surface of the top storey, not to the roof. Ignore a top storey that is only rooftop machinery or plant rooms. Where the ground slopes, measure from the lowest point of the ground next to the building.

Counting storeys

Do not count:

• storeys below ground level;
• a storey that holds only rooftop plant or machinery;
• galleries or mezzanines with less than half the floor area of the largest storey above or below.

The guidance says open rooftops, such as roof gardens, are not storeys, and notes the government is consulting on making that explicit.

What counts as a residential unit

A dwelling or any other unit of living accommodation: flats, studios, units in student halls and supported housing. Tenure does not matter. A block of private flats and a block of social housing are treated the same.

Buildings that are excluded

A building is not higher-risk if the whole building is one of these:

• a hospital;
• a care home;
• a secure residential institution;
• a hotel;
• military barracks.

Buildings with Ministry of Defence living accommodation for service personnel are also excluded. Mixed-use buildings are more complicated: a tower with offices below and flats above can still be higher-risk if it meets the test. Take advice if your building does not fit neatly.

What it means for the people responsible

These sit on top of the Fire Safety Order duties, which still apply to the responsible person.

Where passive fire protection comes in

The safety case has to show how the spread of fire is controlled. In a block of flats, that mostly means compartmentation: each flat holding a fire long enough for the people elsewhere to stay safe. You need evidence that:

• compartment walls and floors are intact, including in risers and ceiling voids;
• service penetrations are sealed with tested systems;
• flat entrance and communal doors are fire doors that close and latch;
• cavity barriers are in place in the external walls and voids;
• dampers in ventilation ducts work.

That evidence usually comes from a compartmentation survey, a fire door survey and records of remedial work. Photographs, labels and certificates for each item are what make it useful in the golden thread.

Fire doors in buildings over 11 metres

Separate from the higher-risk regime, the Fire Safety (England) Regulations 2022 already apply to residential buildings over 11 metres: communal fire doors checked every three months and flat entrance doors every 12 months. Every higher-risk building is over 11 metres, so these checks apply too. See our bulletin on how often fire doors need to be inspected.

Building work in a higher-risk building

Any building work, including some remedial fire safety work, now goes through the Building Safety Regulator rather than a local authority or private building control body. That adds time. Before starting larger compartmentation remediation, check with your contractor and the regulator whether approval is needed and allow for it in the programme.

Common questions

My building is 17.5 metres but has 7 storeys. Is it in?

Yes. Meeting either the height or the storeys test is enough, as long as there are at least two residential units.

Are student halls included?

Yes, if they meet the height or storeys test and have at least two units of living accommodation.

What about Wales and Scotland?

This regime applies in England. Wales and Scotland have their own building safety rules and reforms; check with the relevant government or your fire risk assessor.

This bulletin is general guidance, not legal advice.