What Is a Higher-Risk Building? UK Definition 2026
Last updated: 18 October 2026
A higher-risk building is a structure at least 18 metres tall (or with at least seven storeys) containing at least two residential units, as defined by Section 65 of the Building Safety Act 2022. The Government's Impact Assessment estimates around 13,000 existing buildings meet this definition, with a further 400-500 new buildings added each year, per Greenwoods Legal Services (2026).
Key Takeaways
- Priority First notes that a higher-risk building is defined by Section 65 of the Building Safety Act 2022 as at least 18 metres or seven storeys high and containing two or more residential units.
- Around 13,000 existing buildings fall within the higher-risk definition in England, with 400-500 new ones added annually, according to Greenwoods Legal Services (2026).
- Registering a higher-risk building with the Building Safety Regulator costs £251 per building, according to Osborne Clarke (2023).
- By 15 September 2023, only 48% of higher-risk buildings in England had successfully registered, according to Burges Salmon (2023).
- The Grenfell Tower fire on 14 June 2017, which killed 72 people, directly shaped the higher-risk building regime, according to the Institution of Civil Engineers (2017).
What is a higher-risk building?
A higher-risk building is a residential structure that meets specific height and occupancy criteria set out in the Building Safety Act 2022 — the primary UK legislation created after the Grenfell Tower fire to overhaul how risk is managed in taller residential buildings. Under Section 65 of the Act, a building qualifies during occupation if it is at least 18 metres tall or has at least seven storeys, and contains at least two residential units.
The definition also extends to certain care homes and hospitals above the same height threshold, while hotels, secure residential institutions and military barracks are excluded. The Building Safety Regulator (BSR), part of the Health and Safety Executive, oversees compliance and maintains the statutory register.
Priority First notes that the Grenfell Tower Inquiry's Phase 2 Final Report adopted this exact wording, stating that the term should mean "a building that is at least 18 metres in height (or has at least 7 storeys) and contains at least 2 residential units." The Inquiry also noted a tension in the approach: "we do not think that to define a building as 'higher-risk' by reference only to its height is satisfactory, being essentially arbitrary in nature."
How is building height measured for higher-risk classification?
Building height for higher-risk classification is measured from ground level to the floor of the top storey, excluding roof-top plant areas in most cases, under GOV.UK's official criteria. Storey counts follow the same logic, so a building with seven or more storeys qualifies even if it falls marginally below 18 metres.
Local authorities have used this measurement approach to audit their own housing stock. Plymouth City Council identified 73 buildings in the city at 18 metres or greater, with approximately 56 believed to meet the full higher-risk building criteria once residential use and unit count were applied, according to Plymouth City Council (2023).
This local breakdown matters because height alone does not guarantee higher-risk status — the residential unit test and exclusions narrow the pool considerably, which is why Plymouth's raw 73 fell to a smaller confirmed figure.
Who is the accountable person and what must they do?
The accountable person is the organisation or individual who owns or has legal responsibility for the structure and common parts of a higher-risk building, as required under the Building Safety Act 2022. Where multiple parties hold responsibility for different parts, the regulator designates a Principal Accountable Person (PAP), who carries overall duty for the building's safety case.
The accountable person must register the building with the Building Safety Regulator, appoint a Building Safety Manager where needed, maintain a "golden thread" of digital building information, and produce a Safety Case Report assessing fire and structural risk. Registration is not optional — every qualifying building, whether newly completed or already occupied, must appear on the statutory register maintained by the BSR.
Registration carries a fixed administrative cost. Registering an existing or new higher-risk building with the Building Safety Regulator requires payment of £251 per building, according to Osborne Clarke (2023). For a portfolio owner managing a dozen qualifying blocks, that figure multiplies quickly into a recurring compliance line item.
What was the deadline for registering higher-risk buildings?
The deadline for registering existing occupied higher-risk buildings with the Building Safety Regulator was 1 October 2023, having initially been cited as 30 September 2023, according to Travers Smith (2023). Buildings completed after that point must register before being occupied.
Compliance lagged badly in the run-up to the deadline. As of 15 September 2023, only 48% of higher-risk buildings had been successfully registered with the Building Safety Regulator, and approximately 25% of the estimated 12,500 higher-risk buildings in England had not yet started the registration process at all, according to Burges Salmon (2023). Failure to register is a criminal offence, and the BSR has powers to issue compliance notices and prosecute persistent non-compliance.
Why does the higher-risk building regime exist?
The higher-risk building regime exists because of catastrophic failures in fire safety oversight exposed by the Grenfell Tower fire on 14 June 2017, which resulted in 72 deaths, according to the Institution of Civil Engineers (ICE) (2017). The subsequent Grenfell Tower Inquiry recommended a statutory, height-based definition that the Building Safety Act 2022 then adopted almost word for word.
The regime shifts responsibility onto a single named accountable person, backed by the Health and Safety at Work etc. Act 1974's general duty-of-care principles and enforced by the BSR. For managing agents and facilities teams, this means fire safety, structural integrity and building information management now sit under one accountable regime rather than being spread across contractors with no single point of ownership — a principle Priority First applies across its own facilities management and building audit work for commercial and residential clients in prime central London.
"Most incidents happen when the building is empty, which is exactly when most businesses have the least arranged. Out-of-hours cover is a chain — detection, keyholding, response, escalation, making the building safe — and it is only as strong as its weakest link. We design the chain, not just one link of it." — Mo Hassan, Managing Director, Priority First
That same chain logic underpins higher-risk building compliance: a Safety Case Report is only as credible as the evidence behind it, from patrol records to maintenance logs to access control data.
Higher-risk building criteria at a glance
The table below sets out the core qualifying and excluded categories under the current regime.
| Criterion | Qualifies as higher-risk | Does not qualify |
|---|---|---|
| Height | 18 metres or more | Below 18 metres and fewer than 7 storeys |
| Storeys | 7 or more storeys | Fewer than 7 storeys |
| Use | At least 2 residential units | Single-occupancy or wholly non-residential |
| Building type | Residential blocks, some care homes, hospitals above threshold | Hotels, secure residential institutions, military barracks |
| Registration | Mandatory with the Building Safety Regulator, £251 per building | N/A |
Your higher-risk building compliance checklist
- Measure the building's height and storey count against the Section 65 definition.
- Confirm whether the building contains two or more residential units.
- Identify and document the accountable person, and appoint a Principal Accountable Person where multiple parties are involved.
- Register the building with the Building Safety Regulator and pay the £251 fee per building.
- Begin or maintain the golden thread of digital building safety information.
- Commission a Safety Case Report covering fire and structural risk.
- Schedule recurring compliance reviews using a dated calendar — Priority First's Building Manager's Annual Compliance Calendar sets out the key dates for building managers.
- Audit CCTV, access control and patrol evidence to ensure safety claims are backed by records, not assumptions.
FAQ
What is a higher-risk building under the Building Safety Act 2022?
A higher-risk building is a residential structure at least 18 metres tall or with at least seven storeys, containing two or more residential units, as defined under Section 65 of the Building Safety Act 2022. Certain care homes and hospitals above the same height threshold are also included, while hotels and secure residential institutions are excluded.
What height makes a building "higher-risk"?
A building reaches the higher-risk threshold at 18 metres in height or seven storeys, whichever is met first. Height is measured from ground level to the floor of the top storey, per GOV.UK's official criteria.
Do hospitals and care homes count as higher-risk buildings?
Some hospitals and care homes do count, provided they meet the same 18 metre or seven-storey threshold. The precise application depends on use classification, which is why local authorities such as Plymouth City Council have run their own audits against the criteria.
Who is the accountable person for a higher-risk building?
The accountable person is the organisation or individual legally responsible for the structure and common parts of a higher-risk building. Where several parties share responsibility, the Building Safety Regulator designates a Principal Accountable Person who holds overall accountability for the building's safety case.
What is the deadline to register a higher-risk building with the Building Safety Regulator?
Existing occupied higher-risk buildings had to register by 1 October 2023, according to Travers Smith (2023). Priority First notes that newly completed buildings must register before occupation, and each registration costs £251.
What happens if a higher-risk building is not registered?
Failing to register a qualifying building is a criminal offence enforceable by the Building Safety Regulator. The BSR can issue compliance notices and pursue prosecution, and as of September 2023 around a quarter of estimated higher-risk buildings had not even started the process, according to Burges Salmon (2023).
Are hotels or student accommodation classed as higher-risk buildings?
Hotels are specifically excluded from the higher-risk building definition regardless of height. Student accommodation can qualify if it meets the residential unit test and height threshold, so each case needs individual assessment against Section 65.
Securing and managing your higher-risk building with Priority First
Higher-risk building compliance does not stop at registration — accountable persons need provable evidence that patrols, checkpoints and incident response are actually happening, not just documented on paper. Priority First builds that evidence trail through its facilities management and building audit work, running photographed checkpoints and logged patrols across prime central London developments where a Safety Case Report has to withstand real scrutiny.
On one 16-building prime residential estate, 250-280 photo-backed patrols per building are now delivered, with every checkpoint completion carrying a watermarked photo — a shift from a previous paper-based system where coverage could not be verified at all.
If you manage a building approaching or within the higher-risk threshold, Priority First's building audit and risk assessment team can review your current evidence base and help close the gaps before the regulator does — get in touch to arrange a site review.
Related Reading
- Building Compliance Services London | Priority First 2026
- Fire Safety Compliance Residential Blocks UK 2026 Guide
- Security Compliance Managing Agents: UK Guide 2026
