Policy paper

Definition of higher-risk buildings: initial review and plans for ongoing review

Published 17 December 2025

Applies to England

Introduction

On 28 April 2022, a significant shift in the regulation of higher-risk buildings took place with the passage of the Building Safety Act. Starting in October 2023, this introduced the Building Safety Regulator (BSR) as the building control authority for higher-risk building work. The Act also created strong ongoing duties to manage risks for those responsible for existing Higher-Risk Buildings.

The building control changes marked a move away from the previous system, where building control was delivered by local authorities and private sector bodies, each operating under distinct procedures. These legacy procedures continue to apply to non-higher-risk buildings, with the initial focus of reform placed on those buildings that pose the greatest safety risks.

Under the former local authority route, building work could begin before formal approval of plans was granted. If no response was received within the statutory timeframe, plans were automatically deemed approved. Even when plans were rejected, work could still proceed, with enforcement powers rarely exercised. In the private sector route, the emphasis was on transferring building control duties through contractual arrangements, with no mandatory plan assessment and limited enforcement tools.

Both systems lacked a requirement to produce updated plans reflecting completed work, resulting in gaps in critical building information. This made it difficult to assess future maintenance needs or manage buildings effectively over their lifecycle. The previous systems also contributed to a reliance on building control professionals for assurance, rather than fostering broader competence across the industry.

While the system enabled smooth project progression with minimal disruption, the absence of consistent oversight and enforcement created vulnerabilities that became tragically evident in events such as the Grenfell Tower fire and the subsequent cladding crisis.

There was also little regulation of those responsible for the management of existing higher-risk buildings before the Act. There were no clearly identifiable dutyholders for many buildings, and there was a lack of expectation for building safety to be proactively maintained. Residents were often not involved in decision-making, and key information was not required to be available to them. These flaws were horribly exposed by the Grenfell Tower fire.

The new regime seeks to address these systemic issues by introducing clearer accountability, stronger regulatory oversight, and a more consistent approach to safety in higher-risk buildings. It represents a step change in how building safety is managed, with the aim of restoring public confidence and ensuring that buildings are safe now and in the future.

Executive Summary

Background

The Grenfell Tower fire in 2017 was a national tragedy. In response, the government commissioned the Independent Review of Building Regulations and Fire Safety, led by Dame Judith Hackitt. This review identified the fundamental changes needed to prevent such a disaster from ever happening again. The final report laid out clearly that the existing system of building regulations was not fit for purpose and, amongst other recommendations, proposed a new framework for regulating high-rise residential buildings.

The government accepted these recommendations, and in some areas went further. In the Building Safety Act 2022, the government implemented a new, more robust regime for buildings defined as higher-risk buildings.

Under the Building Safety Act 2022 and its supplementary regulations, a higher-risk building is defined as a building that:

• is at least 18 metres in height, or has at least 7 storeys
• contains at least 2 residential units
• does not comprise entirely of a secure residential institution, a hotel or military barracks; and does not contain Ministry of Defence provided living accommodation or living accommodation for His Majesty’s Forces or for any designated visiting force, international headquarters or defence organisation

Under Part 3 (design, construction, and building work to existing higher-risk buildings), hospitals and care homes are included in the higher-risk regime. However, under Part 4 (in-occupation duties), they are excluded. 

The new legislation and regulations introduced a fundamental reform in how higher-risk buildings are designed, constructed, and managed. They changed the building control process to impose new duties on those procuring, designing, and constructing higher-risk buildings. These duties extend to accountable persons responsible for managing the buildings, ensuring that safety and performance are embedded from the design stage throughout the building’s entire lifecycle.   

The Building Safety Act 2022 made the Building Safety Regulator (the Regulator) the building control authority for these buildings; solely responsible for overseeing compliance with building regulation requirements. Additionally, to ensure the higher-risk framework remains responsive to emerging evidence, the Act gives the Regulator a duty to recommend changes to the definition of a higher-risk building for either Part 3 or 4. If the Regulator  believes a building poses a greater safety risk than others – and that this risk could lead to a major incident if materialised – it can advise that those buildings should fall within the scope of the higher-risk regime in England.

The Grenfell Inquiry Recommendation

Shortly after the fire, the government commissioned the Grenfell Tower Inquiry “to establish the facts of what happened at Grenfell Tower, in order to take the necessary action to prevent a similar tragedy from happening again”.^{[footnote 1]}

The Inquiry’s Phase 2 report made the following recommendation: (113.7)

For the purpose of this and our other recommendations we have used the expression “higher-risk building” in the sense in which it is used in the Building Safety Act, that is, a building that is at least 18 metres in height (or has at least 7 storeys) and contains at least 2 residential units. However, 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. More relevant is the nature of its use and, in particular, the likely presence of vulnerable people, for whom evacuation in the event of a fire or other emergency would be likely to present difficulty. We therefore recommend that the definition of a higher-risk building for the purposes of the Building Safety Act be reviewed urgently.

The government accepted the Inquiry’s recommendation and asked the Regulator to undertake an initial review of the evidence to inform a decision as to whether there should be any change to the definition of a higher-risk building. The Regulator’s view is that, at the time of publication, there is insufficient evidence to suggest changes should be made – further detail is set out below. This view is supported by the Ministry of Housing Community and Local Government (MHCLG).

However, both the Regulator and MHCLG recognise that the UK’s built environment is evolving at pace, and that the higher-risk building regime needs to be responsive to emerging evidence and issues. The Regulator and MHCLG have therefore agreed that the Regulator will operate an ongoing review of the definition of a higher-risk building, alongside its duty to keep the safety and standards of all buildings under review.^{[footnote 2]} This ongoing risk-based review will provide a framework for the Regulator to consider the impact of new developments and changes to risk in the built environment on the scope of the Higher-Risk Building regime in a continuous and structured manner.

The Regulator will also be working with the government as it continues to implement other reforms to ensure that the safety needs of vulnerable people are considered, such as the introduction of residential Personal Emergency Evacuation Plans (residential PEEPs).

This document contains 3 parts:

• an overview of the current regime, including the additional duties for those who are involved in building work and managing higher-risk buildings; and the rationale for the current definition of a higher-risk building
• the review of the current regime, following the recommendation. This evaluates the benefits, risks and impacts a change to the definition of “higher-risk building” would have
• the plans for an ongoing review

Part 1: The Current Higher-Risk Regime

Overview   

The higher-risk regime reformed the way these buildings are designed, built regime made landmark changes to the building control process for higher-risk buildings, providing ‘hard stops’ that ensure developers consider the building regulations at all stages of design and construction. It introduced mandatory occurrence reporting requirements during construction phase and the requirement to appoint competent people. It also placed new duties on accountable persons responsible for existing buildings to make sure that they are being managed on an ongoing basis.

The design and construction provisions in the Act (Part 3) make the Regulator the sole building control authority for higher-risk buildings and introduce new procedural requirements for building work to these types of buildings. The regulator must now give approval before any building work on or to higher-risk buildings can commence, including construction of new buildings – this stage is known as Gateway 2. Major changes during the process must also be approved by the Regulator through the change control process.

This process does not apply to work:

• that is exempt^{[footnote 3]}
• carried out under a Competent Persons Scheme^{[footnote 4]}
• is an emergency repair^{[footnote 5]}

Once completed, the building (if newly built) can only be occupied once the Regulator has approved the construction and certified that the building meets the requirements of the building regulations – known as Gateway 3 - and issued a completion certificate.

The in-occupation sections of the Act (Part 4) require those responsible for managing higher-risk buildings to register those buildings with the Regulator. Accountable persons (APs) must make assessments of building safety risks^{[footnote 6]} and must take all reasonable steps to prevent a building safety risk materialising and to reduce the severity of any incident that may occur.

The principal accountable person (PAP) is then responsible for preparing the safety case report containing any assessments of the building safety risks and steps taken by an AP as above. The PAP must prepare and review the residents’ engagement strategy for promoting the participation of residents and the owners of residential units in the making of building safety decisions and must act in accordance with the strategy.

The PAP must establish and operate a mandatory reporting system, and APs must comply with the mandatory reporting requirements for recording certain building safety incidents or situations. APs must register a building and give the prescribed information to the Regulator, residents and other persons, and under the direction of the Regulator, apply for a Building Assessment Certificate (BAC).

The Regulator will either:

• approve a BAC for the building
• issue a contravention notice under section 81(4) Building Safety Act 2022 if it considers a contravention can be remedied promptly
• will refuse to issue the certificate and consider enforcement action

For further details, see the government guidance pages for design and construction, and in-occupation. 

Rationale for the current definition

This section describes the processes that led to the original decisions on the scope of the higher-risk building framework, including expert views and statistics. Updated statistics are considered in the next section.

Building a Safer Future

Following the tragedy of the Grenfell Tower fire, the government set up the Independent Review of Building Regulations and Fire Safety, chaired by Dame Judith Hackitt. The recommendations of the final report  formed the base of the current regulatory regime. The aim was to establish a system focused on preventing incidents that could cause multiple deaths or life-changing injuries. Dame Judith Hackitt recommended that higher-risk buildings be defined as any building 10 storeys or above that were either fully or partially for residential use. 

The review made this recommendation by considering the following factors:  

• Home Office Fire Statistics. At the time of the report (Sept. 2017), these showed that there was a significantly higher rate of fatalities (per 1,000 fires) in residential or mixed use (including residential) buildings than other categories. In particular, the rate of fatalities was more than 3 times as high as in other properties where people sleep, such as hospitals and hotels. Thus, she recommended the regime apply to residential, or mixed use (including residential), buildings only.
• Home Office fire statistics and ones from the English Housing Survey, analysed by Building Research Establishment (BRE), suggested that height was a significant factor in both the fire rate (10 storeys+ buildings had more than twice the rate of fires as those below) and the fatality rate (10 storeys+ buildings had around 3 times as many deaths per 1,000 fires as those below). Therefore, Dame Judith Hackitt felt that storey height was an appropriate factor to classify higher-risk buildings, and that 10 storeys was the right threshold.
• approved documents are guidance on ways to meet building regulations. Approved Document B (Fire Safety) already relies upon both the purpose of the building, and the height of the building, to inform safety provisions in a building. Approved Document A (Structure) meanwhile uses ‘building consequence classes’, which include the height, number of storeys and use category. These were the only 2 approved documents to differentiate risk based on these kinds of factors.

The report acknowledged that the fatality rate was much higher in multi-occupied residential buildings; therefore these would be the “most relevant [buildings] to target the more intensive regulatory framework” on, in order to ensure proportionality.

The report did however emphasise the importance of adaptability to future changes, based on the emergence of new information, and suggest that a “reasonable ambition” in the future might be to include a wider set of buildings where people sleep, such as hospitals and care homes, which are normally less than 10 storeys.

The Building Safety Act 2022

Following the Independent Review recommendation, the government stated that they would focus the new regime on buildings where a significant incident would put many lives at risk.  The government confirmed that the new regime would apply to the buildings that had been laid out, but that further research and consultation would be undertaken to determine whether the definition of a higher-risk building should be extended further.^{[footnote 7]}

During this research and consultation, the government came to the view that a threshold of 18m+ was more appropriate for the following reasons:

• many stakeholders during the initial consultation felt that a 10 storey threshold included too few buildings, and that more mid-rise buildings should come under the new regime
• the Home Office undertook further research which found that “rates of fires were considerably higher in apartment blocks over 18 metres (43 fires per 1,000 buildings between 18 metres and 30 metres) (366 fires per 1,000 buildings 30 metres and above) in comparison to apartment blocks of any height (9 fires per 1,000 buildings).”^{[footnote 8]}

Expert advisers consulted by the government (including Dame Judith Hackitt and Sir Ken Knight) gave the following advice:

In most cases in blocks of flats below 18m where fire safety risks are identified (such as the presence of combustible cladding), adequate levels of safety can be achieved for residents by implementing cost effective risk mitigations (such as smoke and fire detectors and alarms, adequate means of escape, sprinklers and smoke control systems).^{[footnote 9]}

The government recognised the need for objective, measurable criteria in the new regime. Based on available evidence and stakeholder views, it concluded that setting the threshold below 18m could be disproportionate. Therefore, 18m was determined to be an appropriate threshold for defining higher-risk buildings. 

The government then held a public consultation. In the government response, it was noted that most respondents “believed that a wider set of buildings should be in scope from the outset”, but that ”there was no overall consensus over other factors (than height) that should determine in scope buildings”.^{[footnote 10]} 

Additionally, the consultation led to the criteria of 7 storeys or above being added to the 18m+ threshold. This was in response to concerns from stakeholders around potential gaming of a solely height-based threshold. 

This led to the definition of a higher-risk building as enacted in the Building Safety Act. The Act was drafted to allow the government to make supplementary regulations to define “building” and “storey”, to make provision for the determination of the height of a building, and to exclude buildings of a prescribed description from the definition of an HRB.

The Higher-Risk Buildings (Descriptions and Supplementary Provisions) Regulations 2023

Once the overall scope of the regime had been decided, the government then took a view on which non-residential buildings where people sleep should be included. It was decided that buildings which are entirely comprised of a secure residential institution, a hotel or military barracks, or contain Ministry of Defence provided living accommodation or living accommodation for His Majesty’s Forces or for any designated visiting force, international headquarters or defence organisation should not be included in either the Part 3 (building control) or Part 4 (in-occupation) sections of the Act.  Prisons and MoD accommodation were excluded from Part 3 (design and construction) because they have their own regulations, and hotels were excluded as fires rates were considerably lower than prisons and hospitals.

In response to strong views in the Building Safety Act public consultation, it was decided that hospitals and care homes should be included in Part 3, in recognition of the higher likelihood of vulnerability of the hospital and care home building users. This was to ensure work undertaken on existing buildings, or the design and construction of new buildings that meet the height or storey criteria for a higher-risk building, is covered by the new safety measures, especially where it may be occupied by those who cannot evacuate quickly or without assistance.

Care homes and hospitals were not included in Part 4 (in-occupation) because the Regulatory Reform (Fire Safety) Order 2005 already applies to these buildings, and because many of the new duties introduced were not relevant to them. 

The government also took on Dame Judith Hackitt’s view that care homes and hospitals were covered by other legislation. As the minister speaking for the government said at the Grand Committee debate in the House of Lords, “Dame Judith Hackitt recommended focusing on residential buildings, and we agree that occupied non-residential buildings are already adequately and proportionately regulated through other legislation.^{[footnote 11]}

The government also undertook a public consultation on this legislation. The government response noted that responses to questions about which buildings should be included were varied and concluded that no changes were required. 

As required under the Building Safety Act 2022, the Secretary of State wrote to the Regulator seeking advice. Following research conducted by the Regulator’s Science Division, which suggested the draft regulations were appropriate, the Chief Inspector of Buildings responded advising this and that there was no need to extend scope. 

Part 2: The Building Safety Regulator’s Initial Review

Overview

Following the publication of the Grenfell Inquiry report, the MHCLG asked the Regulator to undertake a review of the current higher-risk regime. The Regulator concluded this review in February 2025. This review considered the key factors and what implications they hold for the current scope of the higher-risk building regime, including:

• current statistics
• vulnerable occupants
• impact on industry
• impact on safety aims of the regime
• interaction with other safety regulation
• cost implications
• capability and capacity of the Regulator and the wider building control sector
• stakeholder views gathered by the Regulator and MHCLG

Current statistics

Height

Updated versions of the evidence that Dame Judith Hackitt and the government examined on the effectiveness of height as criteria for the regime suggest this is still an appropriate tool for the original purpose of the regime. 

Ministry of Housing, Communities and Local Government fire statistics show that between April 2010 and March 2025, there were: 

• 10.8 fatalities per 1000 fires for 10 storey+ flats
• 4.3 for 4-9 storey flats
• 5.7 for 1-3 storey flats^{[footnote 12]}

This indicates that height remains a direct correlation to fatality risk, and that the existing height threshold is currently ensuring that the framework remains targeted on mitigating the risk of the most dangerous incidents, as designed.  

These figures include the Grenfell Tower fire, which, while it significantly changes the statistics due to its scale and severity, starkly illustrates the catastrophic potential of high-rise fires and reinforces the importance of maintaining a height-based regulatory focus. 

These statistics also show that though there has been an overall decline in the number of fires per year since the Independent Review, it remains significantly higher in 10+ storey flats than other categories. Compared to the period between April 2010 and March 2017, the average number of fires each year was: 

• 12.3% less in 10 storey+ flats across the country between April 2017 and March 2025
• 3.8% less fires per year in 4-9 storey flats
• 13.5% less fires per year in 1-3 storey flats ^{[footnote 13]}

This therefore suggests that the existing height threshold should not be decreased, as 10 storey+ buildings have the greatest fire and fatality per fire risk. Due to the lack of a breakdown between 4-6 storeys and 7-9 storeys in fire statistics, it is difficult to tell whether targeting the regime at buildings between 7-9 storeys remains appropriate; however, there is no evidence that there have been any significant changes or an increase of risk since Parliament passed the Act. Whilst there is evidence to consider a change to regime to cover 10+ storeys, we will consider this further later in the document. 

As the higher-risk building regime matures, it is likely that more data will become available on the 7 storey threshold specifically. This will allow future review work on the definition of a higher-risk building to be more targeted on this, rather than relying on data where the split is 10 storeys+ buildings.

Non-residential buildings

Available evidence on fires in non-residential buildings comes from the same fire statistics referenced above. These contain categories for hospitals and medical care; and hotels, boarding houses and hostels, not broken down by height.

These show that between April 2010 and March 2025, there were:

• 0.82 fatalities per 1000 fires for buildings defined as hospitals or providing medical care
• 1.85 for hotels, boarding houses, hostels, and other similar accommodation ^{[footnote 14]}

And, compared to the period between April 2010 and March 2017, the average number of fires each year was:

• 28.6% less in hospitals and other buildings that provide medical care across the country between April 2017 and March 2025
• 24.4% less fires per year in hotels, boarding houses, hostels, and other similar accommodation ^{[footnote 15]}

While every death or injury is tragic and should sought to be prevented, this does suggest that fatalities arising from fires in hospitals and hotels are significantly lower than residential buildings, and that the number of fires overall is falling faster than in residential buildings. This suggests that the needs of vulnerable people in these environments are being met by existing fire risk mitigation measures and regulations, and reforms the government has already made.

Vulnerable occupants and the higher-risk building regime

One of the goals behind the original definition of a higher-risk building was to ensure that it could be clearly understood and applied. The current definition is objective – 2 different people looking at the same building will come to the same conclusion about whether it is a higher-risk building.

This is crucial for allowing industry to adjust effectively to the regime and preventing confusion around which buildings are in scope of the higher-risk regime impacting their work. Similarly, the Regulator needs to have a clear understanding of which buildings are within its remit. Allowing subjective factors to be included would create uncertainty and inconsistencies as to whether a building was within or out of scope of the higher-risk building regime.

Height and use are 2 of a small number of objective factors which can be used to classify buildings and have identifiable thresholds when it comes to buildings and their safety. Occupant vulnerability is a subjective factor.

Aspects which affect how it influences the risk to occupants include:

Degree of vulnerability

Ranges from mild limitations (e.g. slower movement) to complete immobility.

Type of vulnerability

• physical: mobility, sensory impairments
• cognitive: memory, understanding, decision-making
• psychological/emotional: anxiety, PTSD, autism spectrum conditions
• medical: chronic illness, fatigue, medical equipment needs
• social: isolation, lack of support, language barriers

Permanence

• permanent: lifelong conditions
• temporary: injury, pregnancy, recovery
• situational: triggered by specific environments or events

Visibility

• visible: wheelchairs, crutches
• invisible: mental health, neurodivergence, chronic pain

Context dependency

Vulnerability may arise or intensify depending on the situation or environment. Examples include:

• a person with autism may struggle in noisy or chaotic spaces
• non-native speakers may face challenges understanding emergency instructions
• people with anxiety may be more vulnerable in crowded or high-pressure settings

Environmental interaction

How building features (e.g. lighting, acoustics, signage) affect individuals’ ability to navigate or respond.

Occupant distribution

The proportion and concentration of vulnerable individuals - influencing design decisions and emergency planning.

Support needs

Requirements for assistance, technology, or infrastructure to ensure safety and accessibility.

This would make it difficult to include the presence of vulnerable people in the definition of a higher-risk building directly, or through a system such as a matrix of risks and factors. 

This challenge is shown by the fact that in the public consultation held before the Building Safety Act 2022 was brought forward, the government response noted that “there was no  overall consensus over other factors (than height) that should determine in scope buildings”, despite the majority of respondents feeling that “a wider set of buildings should be in scope from the outset”. ^{[footnote 16]}

The presence of vulnerable people remains a key consideration in determining which buildings fall within the higher-risk regime. While height and use are the primary criteria, vulnerability is also considered through the lens of building types with a higher incidence of occupants who may need assistance to evacuate. This is reflected in the inclusion of hospitals and care homes in the design and construction part of the regime, and for work to existing buildings, due to the greater likelihood of vulnerable users. Such considerations will continue to inform decisions about which heights and uses should be captured by the higher-risk framework. 

The government has also made various other changes to ensure vulnerable people’s needs are prioritised.

Approved Document B has been significantly update to address Recommendation 6.3 of the Final Report of the Independent Review of Building Regulations and Fire Safety.^{[footnote 17]} This includes requiring sprinklers to be installed in all new blocks of flats 11m+, and requiring all new care homes to have sprinklers, irrespective of height; it also includes a provision requiring second staircases in new residential buildings over 18 metres which comes into effect in 2026. 

Reforms to the Regulatory Reform (Fire Safety) Order 2005 have also been made by the Fire Safety Act 2021. These include requiring Responsible Persons (RPs) for multi-occupied residential buildings to manage and reduce the fire risks for the structure, external walls and common parts, and to record their fire safety arrangements and all findings in their fire risk assessment. These requirements apply regardless of height. 

Additionally, the government has introduced legislation requiring residential Personal Evacuation Emergency Plans (PEEPs), partially in response to the Grenfell Tower Inquiry Phase 1 recommendations. These changes will include the introduction of distinct residential PEEPs, which will be mandatory for vulnerable residents in all higher-risk buildings and all 11-18m buildings with simultaneous evacuation strategies and must be carried out where the resident consents. 

These changes are specifically targeted to improve the safety of vulnerable people, alongside the more general duties of the higher-risk building regime.

Impact on industry

The regulatory regime operated by the Building Safety Regulator is still relatively new and has had a significant impact on the construction industry. Applicants had not previously been asked to demonstrate compliance with building regulations so thoroughly before being able to start work, and are still adjusting to this process. This is indicated by the fact that as of 7 August 2025, 40% of Building Control Approval Applications have been found to be invalid before even reaching the assessment stage, often because they are missing basic information required by law. The Regulator has also faced challenges operating the regime, including delays in processing Building Control Approval Applications, although we are working to mitigate these as far as possible. 

A change to the definition of a higher-risk building would either increase or decrease the scope of the regime and either add or remove buildings from the regime. Making that change at this time, while the regime is still embedding, would be disruptive to industry.  

Any increase or major change to scope would likely lead to slower construction timelines, impacting businesses and the government’s target to build 1.5 million new homes by the end of this Parliament. A change may also result in some of the additional resources the Regulator is using to upscale operation. 

A decrease in scope could help reduce these pressures. However, it would be highly disruptive to industry, requiring a complex transitional period and would undermine the safety standards we all want to see in our buildings. 

Impact on safety aims of the regime

As of 29 August 2025, only 31% of Building Control Approval Applications and 22% of Building Assessment Certificate applications have been approved under the higher-risk regime. We recognise that this presents real challenges for industry - impacting build-out timelines, operational planning, and delivery.  

However, these figures reflect the regime doing what it was designed to do: stop unsafe or non-compliant buildings from being constructed or occupied. The regime was introduced to raise standards, not change them, and to ensure that buildings are safe for residents from the outset. While the numbers highlight a gap between current industry capability and regulatory expectations, they also show that the system is working to prevent poor-quality work and drive a culture of accountability, competence, and safety. 

Removing buildings from the scope of the regime would reduce this. However, whether the right balance between safety and other factors such as the impact on industry has been struck with the current definition is a policy matter for Parliament and the government. 

The Regulator remains committed to supporting industry through clearer guidance, better tools, and collaborative engagement to help close that gap. This has included: 

• supporting the Construction Leadership Council (CLC) to publish 8 pieces of guidance on building control, with further guidance on staged approvals for new HRBs forthcoming
• engaging in industry-hosted roundtable discussions, seminars and conferences to outline key principles in the new regime
• holding 25 webinars for dutyholders over the last 2 years, including most recently 2 on building control in July 2025, with 4 more to be held in the Autumn
• placing the content of these webinars online (through YouTube) to enable free access to all organisations
• publishing information on ‘what good looks like’ on BSR’s campaign website

Interaction with other safety regulation

There are several other pieces of legislation and regulation which affect higher-risk buildings and buildings that could be considered for inclusion in the regime.

Under the Regulatory Reform (Fire Safety) Order 2005, the Responsible Person (RP) must conduct a fire risk assessment for almost all non-domestic premises. This legislation was updated in 2021 to include the structure, external walls, any common parts and the doors between the domestic premises and common parts in buildings with 2 or more sets of domestic premises. Most respondents, before these amendments, felt that it provided a flexible, risk-based approach to fire safety in non-domestic premises.

As a result, including buildings which are already covered by this legislation in the in-occupation part (Part 4) of the Building Safety Act 2022 would not change the risk assessment needed. The additional requirements added would be a duty to keep more information (the Golden Thread); requirements for a residents’ engagement strategy and a mandatory occurrence reporting system; and for the Regulator to assess the documents.

Additionally, there are a number of inspection regimes required under law in non-domestic buildings, such as those carried out by the Care Quality Commission for hospitals and care homes, and the Crown Premises Inspectorate for prisons. This means that the risk assessments conducted by RPs in these buildings will already be reviewed independently, suggesting that an additional review by the Regulator at the in-occupation stage would result in duplication.

While the addition of the requirement to produce a residents’ engagement strategy and a mandatory occurrence reporting system could be a positive step, it is not likely to have a major impact, and the duplication of work would make inclusion of buildings covered by other regimes problematic.

Cost implications

There are various levels at which an increase to the scope of the higher-risk building regime could apply additional costs and increased construction timelines. In addition to the impact of an increase to the scope of Part 3 (design and construction) to industry as discussed earlier, including more buildings in Part 4 (in-occupation) could lead to increased costs to industry and residents of those buildings. High costs for residents have been repeatedly raised as a concern at the Regulator’s Statutory Residents’ Panel, and for these to be incurred where the evidence suggests a building is not at higher-risk, including for work to existing buildings, would be unfair.

Another area of increased costs would be to the Regulator itself, some of which would come from public funds. Whilst fees for services are chargeable at a cost recovery basis,^{[footnote 18]} changes to the definition of a higher-risk building would result in changes to the Regulator’s functions and required personnel – both operational and non-operational. For example, a drop in the height threshold for residential blocks to 11m+ would add between 71,000-79,000 buildings, increasing the number of higher-risk buildings approximately 7-fold.^{[footnote 19]} This would require large increases in funding, as well as creating capability issues (next sub-section).

A decrease in the scope of the regime would, in principle, reduce costs associated with any buildings removed, and could allow less money to be spent on the Regulator. However, this would require a complex transitional period requiring policy and operational approaches to be adapted for buildings currently within the system.

Capability and capacity of the Regulator and wider building control sector

While the Regulator could in theory simply have its budget increased to deal with an increase in scope, this would not guarantee we can recruit enough individuals with the necessary skills to carry out the additional duties. The Multi-Disciplinary Teams (MDTs) which the Regulator uses to assess Building Control Approval Applications and Building Assessment Certificate applications draw on a limited pool of specialists. In Building Control, this means that the MDTs, which review applications, take on average 5-6 weeks to convene for the first time and begin contributing to a case.

The Regulator is taking steps to speed this up, including through the introduction of a new Fast Track Innovation Unit to quickly process compliant new build applications. The government have also announced reforms to the Regulator,^{[footnote 20]} which include the addition of over 100 members of staff. However, there is still work to do, and an increase in scope i.e. adding new buildings to the higher-risk building framework at this time would slow down the pace of reforms.

Decreasing scope would reduce the acute pressures on the limited pool of specialists used for MDTs and could improve processing times. However, it would lead to buildings, which the evidence suggests should be part of the higher-risk regime, not being included.

Stakeholder views

To understand views on the existing definition of a higher-risk building and how best to improve the protection of vulnerable people, the Regulator consulted with members of our statutory Building Advisory Committee. Those who responded expressed the view that, in the words of one major housing association:

it is important for the new arrangements introduced by the Building Safety Act to be fully established and operating smoothly, both for the regulated and the Regulator, before the scope is amended to include a wider range of buildings.

Another added that “all aspects and ranges of vulnerability cannot be addressed by generic solutions”, and that “the Building Regulations should articulate any requirements for vulnerable people that are necessary”, as a way to protect vulnerable people rather than expanding the definition of a higher-risk building.

The Regulator also considered the views of key stakeholders given in MHCLG roundtables, who felt that defining high risk was difficult and that a more nuanced definition than height would be better, but warned against upsetting the new regime before it has time to bed in.

Conclusion

This initial review has laid out the available evidence on the scope of the higher-risk building regime, both that which was included in the original decision process and new evidence since then.

The original decisions on the definition of a higher-risk building were made with a focus on mitigating the risk and extent of multi-fatality and multiple life-long injuries events like the Grenfell Tower fire. Based on the data available it still seems to be focused on the appropriate categories of buildings.

The review has noted that it would be challenging to use vulnerability as a criteria directly in legislation, along with the wide variety of forms of vulnerability, and has reviewed the other actions taken since the Grenfell Tower fire to protect vulnerable residents.

We also considered that the higher-risk building regime has only been fully operational since April 2024, with dutyholders, stakeholders and the Regulator still working to ensure its effective implementation. Added to this are the pressures produced by the limited pool of specialists available for the Regulator’s MDTs. We therefore conclude that an increase to the scope of the higher-risk building regime at this time would not be right.

However, we also considered the positive impact the regime is already having on buildings within its remit, ensuring the safety and delivery of new higher-risk buildings and the effective management of existing ones. We therefore conclude that it would not be right for the Regulator to recommend a decrease in the scope of the regime.  

As a result, at this time the Regulator does not feel a recommendation to change the scope of the higher-risk building regime would be the right course of action.

However, the Grenfell Tower Inquiry’s recommendation has highlighted the importance of work to protect vulnerable residents. More evidence of the impact on vulnerable people of the higher-risk building regime and other government reforms since the Grenfell Tower fire should be sought and could strengthen the case for changes to the regime in the future.

Additionally, whilst there are challenges in the current delivery, the relative infancy of the regime and policy means there is little indication that the definition of higher risk should be changed at this time. A process to assess whether this remains the case will ensure the government can amend the definition of a higher-risk building if and when evidence supports it.

These considerations, plus the need to consider evolving risks in the built environment and the effect they will have on the higher-risk building regime, have led the Regulator to conclude that we should operate an ongoing risk-based review of the definition of a higher-risk building. This will provide a structured way to ensure the needs of vulnerable people are being considered in the regime and allow the definition to be changed quickly in response to emerging evidence.

The Regulator will also continue to provide input to the government’s other work to protect vulnerable people and ensure long-term, meaningful change is established.

Plan for the ongoing risk-based review

The Regulator and MHCLG recognise that the UK’s built environment is evolving at pace, and that the higher-risk building regime needs to be able to adapt to new and emerging evidence. We have therefore agreed that the Regulator will operate an ongoing review of the definition of a higher-risk building. 

This will operate in conjunction with the Regulator’s duties under Section 5 of the Building Safety Act 2022, which require the following to be kept under review: 

• the safety of people in or about buildings in relation to risks as regards buildings
• the standard of buildings

The Regulator has been drawing on a variety of sources of information to conduct this, including external expertise such as stakeholders and partner regulators, and internal data based on our operation of the higher-risk building regime up to this point. Many of these provide insights into the question of whether the current higher-risk building definition is the most appropriate. 

The review will consider, at least once a year, important evidence such as: 

• new data on fire safety, such as evidence published by MHCLG
• any emerging evidence on vulnerable people, and how their safety is being impacted by other government reforms to the building safety system
• any new and emerging risks in the built environment which are relevant to the spread of fire or structural failure, or the presence of vulnerable people
• an assessment of whether and how changes to the definition would improve protection to residents or users, particularly those who are vulnerable, of a class of building
• stakeholder views
• an assessment of the implications of any changes on sector capacity, the Regulator operations, government policy, or other areas

MHCLG are aware of some concerns with the current policy of splitting buildings into independent sections post-construction, for the purposes of the regime, and will continue to engage stakeholders to explore these concerns further. We are also aware of other risk calculation methodologies and a dynamic building context which is evolving, and will consider this in future reviews.  

The Regulator is also upscaling operations including a horizon scanning function. We will work with the Ministry for Housing, Communities and Local government to consider further research and evidence as appropriate. In addition to this, a review of the Building Safety Act 2022 will be undertaken at the 5-year mark, in 2027. This will ensure that the higher-risk building regime can adapt to new and emerging evidence, and that the protection of vulnerable people is at the heart of government work to reform the building safety system.  

Any proposals for changes will be thoroughly tested with industry and stakeholders before any implementation.  We are committed to maintaining transparency and collaboration throughout the process, and will actively seek feedback to refine any proposals.

1. Written statements - Written questions, answers and statements - UK Parliament. ↩

2. Section 5 of the Building Safety Act. ↩

3. The Building (Higher-Risk Buildings Procedures) (England) Regulations 2023, Schedule 2. ↩

4. The Building Regulations 2010, Schedules 3 and 3A. ↩

5. The Building (Higher-Risk Buildings Procedures) (England) Regulations 2023, Regulation 10.  Note, once complete require BSR to check that the building regulations have been met – a process known as Regularisation. ↩

6. As defined by Section 62 of the Building Safety Act 2022. ↩

7.  [BSP_-implementation_programme.pdf](https://assets.publishing.service.gov.uk/media/5c7554b340f0b603da952a3c/BSP-_implementation_programme.pdf). ↩

8. BSP_consultation.pdf. ↩

9. Independent expert statement in building safety in medium and lower-rise blocks of flats - GOV.UK. ↩

10. On page 14, paragraph 3. ↩

11. Higher-risk building (Descriptions and Supplementary - Hansard - UK Parliament. ↩

12.  From Fire statistics data tables - GOV.UK, based on calculations using table 0205. ↩

13. From Fire statistics data tables - GOV.UK, based on calculations using table 0205. ↩

14.  From Fire statistics data tables - GOV.UK, based on calculations using table 0301. ↩

15.  From Fire statistics data tables - GOV.UK, based on calculations using table 0205. ↩

16. Page 14, paragraph 3. ↩

17. Sprinklers in flats: Approved Document B 2020 Amendments. Sprinklers in care homes: Approved Document B 2025 Amendments. Second staircases: Approved Document B 2026 Amendments. ↩

18. Fee recovery: The Building Safety (Regulator’s Charges) Regulations 2023 and Charging scheme - Building safety - HSE. ↩

19. From Government statistics, May 2022, included in e.g. Estimating the prevalence and costs of external wall system life-safety fire risk in mid-rise residential buildings in England. ↩

20. Reforms to Building Safety Regulator to accelerate housebuilding - GOV.UK. ↩