Research and analysis

Building Safety Remediation: Technical note July 2025

Published 21 August 2025

Applies to England

Data collection

MHCLG uses data from several sources in the Data Release:

1. Building Research Establishment tests;
2. Local authority confirmation – following local authorities providing updates on their own building stock in the social sector and working with building owners and agents to identify any cladding issues, and providing updates on enforcement action;
3. Housing association confirmation – following housing associations providing updates on their own building stock in the social sector and where they act as head lessors in the private sector;
4. Discussions with responsible stakeholders – including building owners, developers, agents and the Local Government Association;
5. Valuation Office Agency property attribute data – to validate the number of dwellings in high-rise residential buildings;
6. Greater London Authority and Homes England (the delivery partners for the ACM Social Sector Remediation Fund, the ACM Private Sector Remediation Fund and the Building Safety Fund Private Sector Applications) – for information relating to the Social and Private Sector remediation funds;
7. Homes England (as delivery partner for the Cladding Safety Fund) - for information relating to the CSS;
8. Homes England (as assessor of eligibility for the Building Safety Fund) – for information on the eligibility of buildings applying to the BSF after April 2024;
9. Developer data reports – for information on buildings covered by the developer remediation contract, including buildings with life-critical fire-safety defects; and
10. Fire Safety Remediation Survey (FRS) – for information on social buildings where the landlord; both private registered providers (PRPs) and local authority registered providers (LARPs), is the responsible entity. The Regulator for Social Housing (RSH) led an aggregate level survey, whilst DLUHC led an individual building level survey on social housing remediation.
11. Ordnance Survey (OS) - for information on building height from the National Geographic Database (NGD).

Since summer 2017 MHCLG have been funding the testing of cladding from high-rise residential buildings at the Building Research Establishment (BRE) . This establishes the category of ACM cladding, which, along with insulation type, determine compliance with Building Regulations. BRE test data for private sector, social sector residential and publicly owned buildings were published in data releases between December 2017 and December 2020.

The data table on samples received by BRE for testing – which was a count of materials submitted to BRE for testing and was previously published each month – was discontinued in October 2019. The data table of descriptions of large-scale system tests undertaken by BRE and the number of buildings with similar cladding systems was discontinued in November 2020.

Since autumn 2017, local authorities have been working with private sector building owners to ascertain combinations of ACM cladding and insulation on high-rise private sector buildings which have not been tested by BRE. Local authorities have used information from sources such as local fire and rescue services, building plans, ACM tests undertaken elsewhere, knowledge of similar buildings where BRE tests have confirmed ACM cladding, and/or building inspections.

MHCLG and local authorities have adopted many approaches to identify the cladding and insulation status of the remaining private sector buildings. This has included the payment of an allowance to local authorities for identifying buildings or starting an enforcement process against building owners, with a cut-off date at end May 2018. The Data Release of 28 June 2018 was the first that included data confirmed by local authorities.

MHCLG are confident that the vast majority of social and private sector high-rise residential and publicly owned buildings with ACM cladding systems unlikely to meet Building Regulations have been identified.

Since spring 2018 MHCLG have been talking with building owners, developers and agents to ascertain updates on remediation. As of 11 February 2019, the questionnaire used to collect information on high-rise residential buildings in England with ACM cladding systems was updated to provide increased precision in response options concerning the status of remediation. This might result in marginal changes in the data as further updates are collected. Additional questions were added which do not impact the data in this release.

Since early 2019 MHCLG have collected data on dwellings from the VOA Property Details data website. We have used this data to provide greater coverage of the number of dwellings in buildings with ACM cladding systems, as well as validating responses from responsible stakeholders.

Since summer 2019 MHCLG has been collecting data on all external wall systems on residential buildings 18 metres and above in height and will publish appropriate information from the data collection when ready. On 21 November 2020, MHCLG published information on estimates of EWS1 requirements on residential buildings in England, including indicative analysis on the cladding coverage of residential buildings and the number of leasehold dwellings in those buildings. This analysis was updated on 8 March 2021 due to a further publication of guidance notes by the Royal Institution of Chartered Surveyors. On 10 January 2022, MHCLG published data for the first time on the number of EWS1 forms (or equivalent) that have been required on mortgage valuations for flats. This data has been published as reported by 7 major lenders in the United Kingdom. For more information please see  EWS1 (or equivalent) lender data on mortgage valuations for flats: April to September 2021, United Kingdom. The data release will be updated on a quarterly basis.

Since the October 2019 Data Release MHCLG has reported on buildings known to be vacant. Buildings are vacated for a variety of reasons. This can be because they are being prepared for demolition or that a Fire and Rescue Service or local authority has issued a prohibition order, preventing residents from using the building. A vacated building that has had its cladding removed and with no further works to take place prior to demolition is considered to have been remediated.

It is known that some buildings have had their ACM cladding removed even though remediation is not yet complete. From March 2020, we have incorporated further information regarding those buildings that have started remediation – where works have finished but are awaiting sign-off, and where cladding has been removed but where works have not finished.

From April 2020 until August 2020 we provided information on the impact of COVID-19 on remediation progress for those remediation projects which have already started remediation.

From May 2020 we have provided more analysis with a focus on remediation in local areas, for both local authorities and other aggregated areas. Local authority data excludes local authorities with fewer than 10 high-rise residential buildings, regardless of whether they have cladding, and groups local authority figures into bands. These disclosure control measures are in place to prevent the identification of one or more buildings with ACM cladding systems unlikely to meet Building Regulations in these areas. Since May 2022, local authorities have been updated to ONS Local Authority Districts December 2021 boundaries. 

From June 2020 we have provided more analysis of the characteristics of all high-rise residential multi-occupied buildings. The methodology of which is described in a section below.

From September 2020 we have robust data on vacant buildings yet to start remediation and these buildings are shown in the charts.

From October 2020 we have published data on remediation progress by tenure for Greater Manchester, London and the Rest of England as a Web Table. 

From December 2020 we have published data on annual remediation progress.

From February 2021 we have published data for vacant buildings in all remediation categories and these buildings are shown in the charts and Web Table.

From April 2021 we have provided more analysis on remediation progress for buildings identified by 31 December 2019 compared to all identified buildings.

From June 2021 we have published quarterly data on Social and Private Sector ACM Cladding Remediation Fund expenditure.

From October 2021 we have published data on the progress of the Waking Watch Relief Fund, previously published alongside the .

From April 2022 we have published data on the progress of the Waking Watch Replacement Fund.

From May 2023 we have published data on the progress of ACM, Waking Watch Relief Fund, Waking Watch Replacement Fund, BSF and Enforcement, in a series of management information tables, previously published separately.

From August 2023 we have published data in the management information tables on Local Authorities attendance of training sessions held by the Joint Inspection Team hosted by the Local Government Association.

From October 2023 we have published data on buildings in the Cladding Safety Scheme (CSS), developer remediation contract, and reported by registered providers of social housing. We have published data on these buildings, as well as ACM and BSF remediation progress all in one data release, with an overall view that accounts for crossover between the different schemes. Data on the number of residential multi-occupied buildings of 11 metres or more is no longer published monthly. Instead, users can find these statistics in the September 2023 data release. An update will be published should the estimates change.

From June 2024, in the BSF tenure reporting, buildings receiving a social sector financial viability claim are now reported on separately rather than being included in the private sector reporting. Prior to June 2024 those buildings with a social sector financial viability claim were counted within the private sector figures as they followed the same funding process as private sector buildings (i.e. received full funding from the government for their remediation works).
Social sector buildings where a Registered Provider of social housing or a local authority have successfully submitted a social sector financial viability claim receive full government funding for remediation. Other social sector buildings in the BSF receive partial funding based on the number of leaseholders that pay a service charge.

From June 2024, we have also changed the methodology in reporting social housing sector remediation under the Social Sector Fire Remediation Survey. The estimates now include social housing buildings that had completed remediation independently of government funding and monitoring schemes before March 2024. They also include social buildings the department is monitoring in other remediation programmes for having unsafe cladding.

From June 2024, enforcement action against 11-18m buildings has been included in the enforcement action figures. Enforcement action is now reported on 11m+ buildings rather than high-rise (18m+) buildings.

From June 2025, we have published data on the progress of the 2023 Waking Watch Replacement Fund. 

From June 2025 we have published data on the estimated number of 11m+ residential buildings 11m+ in height in England that have or had unsafe cladding. This includes an updated estimate of the number of 11-18m buildings and the number of 11-18m buildings with unsafe cladding.   

From June 2025 we have published data on the estimated number of buildings under the developer remediation contract where a determination has been made and where works were started or works were completed in each quarter.

Methodology: Aluminium Composite Material Programme

Local authorities submit a data return on DELTA if they believe a new building is in scope of the ACM programme. MHCLG investigates the building’s eligibility and confirms whether the building is in scope or out of scope. Atkins Réalis (formerly known as Faithful and Gould) are made aware of new buildings in scope of the programme. They then continually engage with responsible entities to track buildings’ remediation progress and report this to MHCLG. Local authorities will also update DELTA with remediation progress updates. Updates received from DELTA are verified with Atkins Réalis where relevant. The monthly remediation progress updates are published.

Buildings in scope of government funding submit an application to the Private Sector Cladding Remediation Fund (PSCRF) or Social Sector Cladding Remediation Fund (SSCRF). Eligible applications are transferred to delivery partners (Homes England or Greater London Authority for PSCRF, or an internal MHCLG team for the SSCRF). Delivery partners provide updates on funding applications to MHCLG, which are published.

Methodology: Building Safety Fund (2020) data

Building Safety Fund data was provided by responsible entities in June and July 2020 to MHCLG through a Survey Monkey Form, registering interest in applying for funding from the 2020 Building Safety Fund. The fund addressed fire safety risks caused by unsafe non-ACM cladding systems. These were buildings with cladding materials and systems that do not meet an appropriate standard of fire safety and could pose a significant risk to the health and safety of residents. There is missing data across a number of fields, for example number of units, and averages are calculated to determine an estimate number of homes and properties.

These registrations are assessed by MHCLG for eligibility for funding and where eligible are passed to the relevant delivery partner (Homes England or Greater London Authority) to engage with responsible entities, data is collected on remediation progress and reported back to MHCLG. All BSF remediation data is provided by responsible entities to the relevant delivery partner. Responsibility for the data lies with the data provider – as such only data provided by delivery partners is published.

When the BSF reopened in 2022 if an application had not already received its Funding Application Board approval or works had not started on site the responsible entity could submit a Fire Risk Appraisal of the External Wall System (FRAEW) and be newly assessed under the new 2022 criteria.

Methodology: Building Safety Fund (2022) data

The Building Safety Fund reopened in 2022 with new eligibility criteria to address life safety risks associated with cladding on high-rise residential buildings. Between July 2022 and April 2024, data was provided by responsible entities to MHCLG through a Citizen Space form and submission of a Fire Risk Appraisal of External Wall System (FRAEW), registering interest in applying for funding from the 2022 Building Safety Fund. The FRAEW can recommend mitigation, partial or full remediation. If a building started remediation after 11 March 2020 but before 28 July 2022 and have not completed remediation, they can still apply under BSF 2022 but under the original criteria.

From April 2024, data for buildings applying to the BSF under the 2022 FRAEW criteria is supplied by responsible entities to Homes England through the Cladding Safety Scheme, who then assess whether a building is eligible for the Building Safety Fund and provide this data to MHCLG on a monthly basis. If a building is under height (below 18m+ with a 30cm tolerance) but otherwise eligible for remediation of its non-ACM cladding systems, its application is progressed through the Cladding Safety Scheme. Buildings applying under the original CAN criteria continue to submit their applications to MHCLG via the Citizen Space form. In rare cases, buildings below 18m+ may have been assessed on an individual basis as eligible for the BSF.

For buildings assessed as eligible by either Homes England (after April 2024) or MHCLG (before April 2024) data is passed to the relevant delivery partner to engage with responsible entities, data is collected on remediation progress and reported back to MHCLG. All BSF remediation data is provided by responsible entities to the relevant delivery partner. Responsibility for the data lies with the data provider – as such only data provided by delivery partners is published.

It is possible for a building to have applied to the Building Safety Fund under the 2020 criteria and also apply under the 2022 eligibility criteria. This means they could be counted as both ineligible and eligible, if ineligible under 2020 criteria and eligible under 2022 criteria. This will affect a small number of buildings only, expected to be fewer than 10.

Methodology: Building Safety Fund (2020 and 2022) data

Some social sector buildings that apply for the Building Safety Fund are said to be financial viability buildings, and have their remediation fully funded by the government. Until May 2024, these buildings were included in private sector building counts, as private sector buildings also receive full funding. To split these out, extensive engagement with MHCLG’s social sector team and programme delivery partners has been undertaken to identify all relevant buildings.

Methodology: Cladding Safety Scheme

The Cladding Safety Scheme (CSS) was opened as a pilot in November 2022, prospective applicants invited to apply to the scheme, and was launched fully in July 2023. Homes England are the delivery partner for the CSS and are responsible for the pull-in process, contacting prospective applicants and encouraging them to apply, the application and eligibility determination process, as well as the delivery of the scheme for eligible buildings.

Data on the application and remediation progress in the CSS is provided in monthly reports, and in the form of monthly data cuts, taken from Homes England’s management reporting system. Given the early stages of the scheme, application progress updates are published, along with remediation progress updates.

Methodology: Developer Data Reports

Developers who have signed the developer remediation contract are required to submit a data report to MHCLG within 30 business days of the date of the Contract. They are also required to submit updated data reports quarterly, by the tenth business day after each reporting date. The report requires developers to submit data on residential and mixed-use buildings of 11 metres and over in height that they developed or refurbished in England over the 30 years ending on 4 April 2022. This includes buildings with life-critical fire-safety defects.

The report includes questions on Fire Risk Appraisal of External Wall assessments (FRAEW) and Fire Safety assessments (FSA), whether a building requires works relating to a life-critical fire-safety defect, the type of defect, remediation progress and start and completion dates, amongst other questions on building level details

The data reports are processed, cleaned, and analysed by a team of analysts within MHCLG, who continually engage with a dedicated team of caseworkers to peer review each report and raise queries regarding data quality. As part of the data cleaning and quality assurance exercise, the reports are linked to other data held by MHCLG, for example data from the Building Safety Fund and Aluminium Composite Material Programme, to impute missing data in the developer’s data report and to identify overlaps across the various government remediation programmes.

Data for developer level statistics are received quarterly, whilst BSF and ACM data are received monthly. This means the period of developer data being used will not always reflect the same period of data being used for other remediation programmes in the Building Safety Release.

MHCLG produce two sets of statistics from the developer reports which are based on different methodologies:

Methodology 1: Developer by developer breakdowns

For estimates published in the quarterly ‘Developer Remediation Contract Data Release’ and management information tables which show breakdowns at a developer-by-developer level, buildings which are being remediated solely under a government remediation scheme are first removed from the data. These buildings are being remediated under the Building Safety Fund or ACM fund, for which the developer will reimburse taxpayers. They are excluded so that estimates reflect the progress on remediation that developers are directly responsible for, rather than a government remediation fund. However, some buildings being remediated under a government remediation scheme will be included if other relevant fire safety defects have been found, which were not eligible for a government remediation scheme and which the developer is remediating themselves.  

Once building being remediated solely under a government remediation scheme are removed, all estimates are based on the raw, self-reported data submitted by developers in their report. A building which has (or has had) life-critical fire-safety defects is identified as a building where the developer has responded ‘Yes - as shown by assessment’ or ‘Yes - the building previously required works which are now fixed’ to the question ‘Does this building require works, or has it previously been identified with defects, as per the contract’. 

The statistics showing the remediation status of buildings are taken from the question ‘Status of Works’. Where the Status of Works is not known or has been left blank by the developer, the status is interpreted as ‘Remediation not started – no plans in place’.

The statistics on building start and completion dates are based on self-reported data and may represent an actual or estimated date as reported by the developer. If an ‘Actual’ start or completion date has been reported this is used by default, otherwise the ‘Estimated’ start or completion date is used.

Methodology 2: Programme and overall view

The estimates published in the monthly Building Safety Remediation Data Release, unless otherwise stated, are based on a combination of self-reported data submitted by developers  and information that has been imputed from Building Safety Fund (BSF) and ACM programme data. held by MHCLG.

There are 4 areas where data is imputed or assumed from other information held by MHCLG or reported by developers in their data report:  

• Buildings identified as having life-critical fire safety defects - A building is reported with life-critical fire-safety defects if:
  • The developer has responded  ‘Yes - as shown by assessment’ or ‘Yes - the building previously required works which are now fixed’ to the question ‘Does this building require works, or has it previously been identified with defects, as per the contract?’;
  • The developer has self-reported the ‘Status of Works’ as Planned, Started or Complete (including those that are awaiting building control sign-off)
  • The building is eligible for funding in the BSF or is being monitored under the ACM programme (including buildings developers have agreed to re-imburse taxpayers for);
  • The building has had money paid out by the BSF or ACM.

• Defect type – where a building has been identified with life-critical fire safety defects but the developer has not reported a defect type in the question ‘What do the issues relate to’ it is assumed that the defect type relates to cladding. Developer buildings estimated with cladding safety defects are published in the ‘Cladding defects’ subsection of the Building Safety Remediation Data Release.

• Dwellings – statistics on the number of dwellings in buildings under the developer remediation contract are taken from the self-reported number of dwellings in the developer data report. However, if the number of dwellings is not known or is left blank an estimate is imputed using an average. This average is based on the known number of dwellings reported by developers, split by height.

• Cost -  statistics on the estimated cost of buildings that have been identified with life-critical fire-safety defects under the developer remediation contract are taken from the self-reported cost of works in the developer data report. However, if the cost is not known or is left blank an estimate is imputed using an average. This average is based on the known reported cost by developers, split by height. The average cost is based on any defect type.

Methodology 3: Estimations of when buildings determined works were required and then proceeded to start and complete remediation

To estimate whether a determination has been made and when works were started or completed MHCLG relies on self-reported data from the quarterly developer data returns. The most recent quarterly returns submitted by developers are used to estimate determinations and works started and completed.  

To estimate when a building had determined if remediation works were required MHCLG uses the responses to the survey question ‘Does this building require works, or has it previously been identified with defects, as per the contract?’. This data is only available from January 2024 when the question was changed to allow more accurate reporting from the developers on whether a determination had been made for each building.  

Buildings reported with a determination in the most recent quarterly return are compared against previous returns and categorised based on the earliest quarterly return in which they were reported to have had a determination, providing they continue to be reported as determined in subsequent quarters. If a determination alternates across returns, the most recent reported data return is used. This method means the most recent returns are given greater weight as developers gather more information about their buildings and further assess what, if any, remediation work is required. 

To estimate the number of buildings where works were started or works were completed MCHLG uses the responses to the survey question ‘Status of Works’. Buildings reported as started or completed in the most recent quarterly return are compared against previous returns and categorised based on the earliest quarterly return in which they were reported to have started or completed works, providing they continue to be reported as started or completed in subsequent quarters. If the response to ‘Status of Works’ alternates across returns, the most recent reported data return is used. MHCLG then adjusts this data to take into account data validation improvements that occurred in January 2025. For buildings where the ‘Status of Works’ has changed from not started/blank to using the new response option in consecutive quarters, the start and completion dates reported by developers are used to categorise the quarter in which they started or completed. For buildings where valid dates were not reported by developers, it is assumed that they had started and completed works before 31 July 2023; the first point at which developers submitted data to MHCLG.

All other developer statistics in the Building Safety Remediation Data Release are based on  self-reported data in the developer data report. For example, the Status of Works, Start and Completion dates.

Methodology: Enforcement

MHCLG has collected data from local authorities on enforcement action taken against 11m+ residential buildings with unsafe cladding in their areas through the work of the Joint Inspection Team, our ongoing engagement, and an online portal. After the monthly data submission deadline set by MHCLG (of which is detailed in the main release) for local authorities, MHCLG begin processing this data ahead of publication. Any returns submitted by local authorities after this deadline will not be processed until the following month’s publication.

The enforcement figures represent 11m+ buildings with unsafe cladding both within and outside of the Private Sector Cladding Remediation Fund, Building Safety Fund and Cladding Safety Scheme. The data only reflects where formal action has been taken; it does not cover the range of informal interactions that local authorities have with those responsible for buildings to progress the pace of remediation. As the data has been collected from local authorities on a voluntary basis, there may be further action that has been taken, of which the department is not yet aware.

From June 2024, the enforcement data now includes enforcement action taken against 11m+ buildings. Previously, it only included high-rise (18m+) buildings.

Methodology: Joint Inspection Team Training

The Joint Inspection Team (JIT) provide training to local authorities on their enforcement powers under the Housing Act 2004. This includes the use of the Housing Health and Safety Ratings System (HHSRS).

The training figures are provided by the LGA and show attendance by local authority of the training sessions the JIT offers: Level 1, Introduction to Fire Safety, Level 2 part 1: Intermediate Fire Safety: Theoretical HHSRS assessments, and Level 2 part 2: Intermediate Fire Safety: Practical HHSRS assessments.

Methodology: Social housing

Landlords, including private registered providers (PRPs) and local authority registered providers (LARPs) were first asked to complete the quarterly Fire Remediation Survey in September 2023 and to report whether they are the Responsible Entity for any residential buildings measuring 11 metres plus or that have 5 or 6 storeys or more, including buildings with life-critical fire-safety defects. The latest survey ran from 13 December 2024 to 22 January 2025, reporting on their buildings as of 31 December 2024.

A ‘Responsible Entity’ is the organisation that has the legal obligation or right to carry out the remediation works. The Responsible Entity may be the building’s freeholder or head leaseholder, registered provider of social housing or a management company or Right To Manage (RTM) company that has primary responsibility for the repair of the property.

The survey required landlords to provide aggregate level information to RSH who led the production of social housing statistics and published separately to the Building Safety Release. In addition to the aggregate survey, landlords were asked to submit fire safety remediation data at an individual building level, which MHCLG have analysed and reported in the Building Safety Release. MHCLG and RSH engage closely to ensure these two releases are as consistent as possible, but there can be discrepancies if the two surveys cannot be fully aligned prior to the data release publication.

Methodology 1: Provider by provider breakdowns

For estimates published in the quarterly  ‘Social Housing Remediation Data Release, and management information tables which show breakdowns at a developer-by-developer level, all figures are based on the self-reported building level data submitted by providers in their data returns. A building which has EWS life-critical fire-safety defects at the time of its most recent works assessment is identified as a building where the provider has responded with the following options:

• ‘Yes’ to the question: ‘As of 31 December 2024, has a building works assessment that complies with the requirements of the Fire Safety Order (for example a Fire Risk Assessment) been undertaken for this building?’; and
• ‘External Wall System’ or ‘Both’ to the question: ‘Based on the most recent Fire Risk Assessment that complies with the requirements of the Fire Safety Order, what do the defects relate to?’

A building which has EWS life-critical fire-safety defects since June 2017 (including a building which was remediated prior to its most recent works assessment) is identified as a building where the provider has responded with the following options:

• ‘Yes’ to the question: ‘Since 14 June 2017, but prior to the building work assessment […], has any building works assessment that complies with the requirements of the Fire Safety Order (for example, a Fire Risk Assessment) identified one or more life-critical fire safety safety (LCFS) issues which require remediation?’; and
• ‘External Wall System’ or ‘Both’ to the question: ‘If you answered “Yes” […], what do the defects relate to?’; or
• ‘Yes’ to the question: ‘As of 31 December 2024, has a building works assessment that complies with the requirements of the Fire Safety Order (for example a Fire Risk Assessment) been undertaken for this building?’; and
• ‘External Wall System’ or ‘Both’ to the question: ‘Based on the most recent Fire Risk Assessment that complies with the requirements of the Fire Safety Order, what do the defects relate to?’

Additionally, buildings where the remediation status is shown as ‘Works not Required’ and the provider indicated in the comments that the buildings would be decanted and were due for demolition have been excluded from the estimates. Duplicate buildings are also excluded in order to avoid skewing the estimates. Where the remediation status is not known or has been left blank by the Registered Provider, this is interpreted as ‘Remediation not started – no plans in place’

Methodology 2: Programme and overall view

The estimates published in the monthly Building Safety Remediation Data Release and statistics on overall remediation e.g., Figures 1 and 2, are based on the self-reported building level survey data and some imputation from other government remediation programmes (BSF, ACM, CSS and the Developer Remediation Contract).

There are 2 areas where data is imputed or assumed from other information held by MHCLG or reported by Registered Providers in their survey data: 

• Buildings identified as having life-critical fire safety cladding defects - A building is reported with life-critical fire-safety defects if:
  • The criteria outlined above is met (please see ‘methodology 1: Provider by provider breakdowns’ for further information)
  • The building is eligible for funding in the Building Safety Fund, Cladding Safety Schee or is being monitored under the ACM programme.
  • The building is reported in the data reports submitted by developers under the developer remediation contract as having cladding safety defects (please see ‘Methodology: Developer Data Reports’ for further information).
• Remediation Status – where a building has been identified with life-critical fire safety cladding defects, the remediation status is based on the status self-reported by Registered Providers in their survey data. However, if this is not known or has been left blank by the Registered Provider, the remediation status is imputed from data in other government remediation programmes (BSF, ACM, CSS and the Developer Remediation Contract). If the status is still not know after this, it is interpreted as ‘Remediation not started – no plans in place’.

Prior to May 2024, the Social Housing Sector statistics reported in the Building Safety Release e.g., Figures 19 and 20, were based on aggregate survey results submitted to the Regulator of Social Housing. In the May 2024 Building Safety Release this methodology was amended and the Social Housing Sector statistics now report on building level data submitted to the Ministry of Housing, Communities and Local Government. They do not account for overlaps with other government programmes.

From June 2024 we also changed the methodology to include buildings which have completed remediation independently of government funding and monitoring schemes before March 2024. We also include social buildings the department is monitoring in other remediation programmes for having unsafe cladding.

Methodology: Waking Watch Relief Fund data

Waking Watch Relief Fund data is provided by applicants to the Waking Watch Relief Fund. There is missing data across a number of fields, for example Waking Watch costs, and averages are calculated on a subset of applications. Some data on Waking Watch costs has been excluded from analysis where outliers have been identified, such as figures that are substantially higher or lower than expected and are judged to be erroneous or on a different basis to that requested.

Average monthly Waking Watch costs per dwelling are based on data for 128 out of 150 approved applications from the first application window, 22 out of 27 approved applications from the second application window and 34 out of 35 approved applications for the third application window. The median waking watch cost per dwelling per month is based on building level data as dwelling level data is not available.

The estimated number of leasehold dwellings covered is based on data for 212 out of 212 approved applications.

Methodology: Waking Watch Replacement Fund data

Waking Watch Replacement Fund data is provided by applicants to the Waking Watch Replacement Fund. There is missing data across a number of fields, for example Waking Watch costs, and averages are calculated on a subset of applications.

Average monthly Waking Watch costs per dwelling are based on data for 22 out of 25 approved applications. The median waking watch cost per dwelling per month is based on building level data as dwelling level data is not available.

The estimated number of leasehold dwellings covered is based on data for 25 out of 25 approved applications.

Methodology: Overall remediation

The overall remediation section of the data release includes buildings with cladding defects only. Buildings can be in multiple schemes and social sector buildings in schemes will also be reported in the Fire Remediation Survey. Therefore, to produce the overall remediation figures for all buildings MHCLG are monitoring, building numbers in each section of the data release cannot be summed. Datasets are matched and buildings appearing in multiple datasets are recorded. The building level social sector Fire Remediation Survey is used and the imputed developer dataset of buildings with cladding defects.

A dataset of buildings and their remediation status is compiled in the following order:

• High-rise (18m+) buildings in the ACM programme (including student accommodation, hotels and public buildings), including those which appear in other data collections
• High-rise (18m+) residential buildings eligible for the BSF, excluding those which are also in the ACM programme
• 11m+ residential buildings eligible for the CSS
• 11m+ residential buildings in the developer remediation contract with unsafe cladding (from the imputed dataset), excluding those which are also eligible for the BSF or which are in the ACM programme
• 11m+ social sector buildings with unsafe cladding reported in the building level Fire Remediation Survey, excluding those which are in the ACM programme, are eligible for the BSF or CSS, or fall under the developer remediation contract

Building level remediation statuses

Where buildings are in multiple data collections or schemes, remediation statuses are assigned from a data collection using the rules above.

For buildings in developer remediation contracts or reported in the social sector Fire Remediation Surveys, which are also in the CSS, ACM programme and or BSF, the CSS, ACM or BSF remediation status is used, rather than the developer or registered provider reported remediation status.

For buildings in the ACM programme and BSF, a combined remediation status is calculated. ‘Remediation not Started’ is assigned for buildings that have not started works on either type of cladding. ‘Remediation Started’ is assigned for buildings where work has started on remediating at least one type of cladding. ‘Remediation complete’ is assigned for buildings that have completed on works for the remediation of both types of cladding.

Estimated dwelling figures

For each building in the overall dataset, the number of dwellings is collated from the dataset the building details are pulled from, following the ordering above. Where the number of dwellings in a building is not known, an average is applied, using the average from the relevant remediation scheme or data collection.

Methodology: Residential buildings (containing dwellings) between 11 and 18 metres in height   

The total number of residential buildings, containing dwellings, between 11 metres and 18 metres in height has been estimated to be between 39,000 and 59,000. This replaces the original estimate published in September 2021. New estimates are based on the recently released Ordnance Survey National Geographic Database (OS NGD) data which was not available when the original estimates were calculated.   

This estimate has been derived from OS NGD data. MHCLG consultants surveyed over 5,000 buildings of varying heights from a randomly stratified sample of OS NGD data. The proportion of buildings in each height band that were found to be between 11 metres to 18 metres were then used to adjust the total number of buildings for that height band in the OS data, using a design and calibration weight system to appropriately weight the sample. This provided an estimated number of 11 metres to 18 metres buildings in each of the height bands which were then summed to provide the overall population of 11 metres to 18 metres buildings.    

The same methodology was followed to estimate the number of buildings between 11-<14m and 14-18m. The proportion of 11-<14m residential buildings in the 11-18m residential buildings population is estimated at 89%. The proportion of 14-18m residential buildings in the 11-18m residential buildings is estimated at 11%   

There are a few key assumptions to this analysis:    

1. In the higher building number range, buildings are defined in line with the OS NGD definition of a building, defined by a unique Building ID. In the central and low building number range, buildings are defined by unique Building IDs and unique parent UPRNs. The different definitions account for varying building definitions across different data collections.    

2. Mixed use buildings, such as shops on the ground floor and self-contained flats on the floors above, are classed as residential buildings by the OS and custodian’s preference.   

3. The OS classification used to define residential buildings of interest is RD06, ‘Self Contained Flat (Includes Maisonette/Apartment)’. Some buildings of interest may be otherwise classified, and some buildings with an RD06 classification code may be incorrectly classified.   

The data quality issues identified could have an impact on our data coverage and therefore overstate or understate the number of 11-18m buildings in scope. These figures represent MHCLG’s best estimate.   

Methodology: Estimating the number of 11-18m buildings with unsafe cladding  

The total proportion of residential buildings, containing dwellings, between 11 metres and 18 metres in height estimated to require work to alleviate cladding related life-safety fire risk is estimated to be between 7.5% and 9.9%.    

It is therefore estimated that between 2,900 and 5,800 residential mid-rise buildings, containing dwellings, require remediation, partial remediation or mitigation to alleviate cladding related life-safety fire risk, of a building population of 39,000 to 59,000 in England.   

This replaces the original estimate published in May 2022, but is based on the same pilot study used to calculate the prevalence of cladding related life-safety fire risk in mid-rise buildings.   

The only changes to the original prevalence methodology are relevant to the following sections of the original publication:    

• Section 3.2: Method: Estimating the population of mid-rise residential buildings in England. See the above section for the new population estimates.    

• Section 3.3: Method: Estimating the prevalence of external wall system life-safety fire risks in mid-rise residential buildings in England. When weighting the estimates to the population, the sampling weights applied to the sample were recalculated to be representative of the new estimated mid-rise building population in England. The new 11-<14m and 14-18m population estimates were also factored into the weighting.    

These figures represent MHCLG’s best estimate.   

Methodology: High-rise residential buildings (containing dwellings)   

The total number of high-rise (18m+) residential buildings, containing dwellings, is estimated to be 12,000. This estimate and methodology is unchanged since 2020.  

Methodology: Estimating the number of 18m+ buildings with unsafe cladding  

MHCLG estimate there are between 2,900 and 3,200 residential buildings, containing dwellings, 18m+ in height that have or had unsafe external wall systems requiring remediation or mitigation work. This represents 24-27% of the 18m+ residential building stock in England.  

Unlike 11-18m buildings, at the time of conducting this methodology (2025) MHCLG already held comprehensive information on residential buildings 18m+ in height requiring external wall system remediation or mitigation in England. As a result, a sample survey of buildings was not required to estimate the total number and instead an assumption based methodology using already held building level data was used.  

At the time of initial publication of these estimates (June 2025), MHCLG were reporting on the remediation progress of 2,899 18m+ buildings, containing dwellings, and an additional 101 18m+ non-dwelling buildings that are hotels, student accommodation and public buildings. This is the vast majority of the estimated 18m+ buildings, containing dwellings, with unsafe cladding.   

To estimate the total number of buildings requiring remediation or mitigation, the buildings already known to MHCLG, as at July 2024, were divided into eight categories. Lower, central and upper estimates for each of the eight categories were then produced based on individual assumptions for those groups.   

Categories i. to v. are all government funded remediation schemes.  

Category vi. Is developer led remediation.  

Category vii. Is social housing provider led remediation.  

The eighth category are buildings that will not enter one of MHCLG’s remediation programmes and therefore will not be reported on in the Building Safety Remediation data release. These buildings are those assumed to require and will complete remediation but which the department is not monitoring the remediation of.  

The eight categories and assumptions were:  

i. 18m+ residential buildings requiring remediation due to the presence of unsafe ACM cladding,  

• In the central estimate: a small number of additional buildings are assumed to require remediation than those known about at the time the estimate was made, based on recent increases in the number of buildings in this category.  

• In the lower and upper estimates: there is a very narrow range around the central estimate to reflect the certainty of stock in this programme.  

ii. 18m+ residential buildings requiring remediation due to the presence of both unsafe ACM and unsafe non-ACM cladding,  

• In the central estimate: a small number of additional buildings are assumed to require remediation or mitigation than those known about at the time the estimate was made, based on recent increases in the number of buildings in this category.  

• In the lower and upper estimates: there is a very narrow range around the central estimate to reflect the certainty of stock in this programme.  

iii. 18m+ residential buildings requiring remediation due to the presence of unsafe non-ACM cladding that applied to the Building Safety Fund in its first tranche of opening,  

• In the central estimate: no further buildings have been forecast to enter the first tranche of the Building Safety Fund as it is closed, though some buildings have been forecast to move to developer funded remediation, based on knowledge of their developer, that have not transferred yet.  

• In the lower and upper estimates: there is no variation from the central estimate due to the certainty of the stock in this programme.  

iv. 18m+ residential buildings requiring remediation due to the presence of unsafe non-ACM cladding that applied or will apply to the Building Safety Fund in its second tranche of opening,  

• In the central estimate: the estimate of further buildings entering the second tranche of the Building Safety Fund is based on recent rates of application and eligibility, and indications from social housing providers of buildings that  will apply for funding in future. 

• In the lower and upper estimates: the application rate and eligibility rate assumptions made to calculate the central estimate are varied.  

• The assumptions on further buildings applying for funding are based on funding eligibility criteria at the time the estimates were made. 

v. 18m+ residential buildings requiring remediation due to the presence of unsafe non-ACM cladding that applied or will apply to the Cladding Safety Scheme,  

• In the central estimate: the estimate of further 18m+ buildings entering the Cladding Safety Scheme is based on recent rates of application and eligibility, and indications from social housing providers of buildings that they will apply for funding in future.  

• In the lower and upper estimates: the application rate and eligibility rate assumptions made to calculate the central estimate are varied.  

• The assumptions on further buildings applying for funding are based on funding eligibility criteria at the time the estimates were made. 

vi. 18m+ residential buildings requiring remediation due to the presence of unsafe non-ACM cladding that are being remediated by developers who have signed the developer remediation contract,  

• In the central estimate: the estimate of further buildings entering this programme is based on an assumption of the proportion of not yet assessed stock that will require remediation or mitigation.  

• In the lower and upper estimates: the assumption made in the central estimate about the proportion of unassessed stock that will require remediation is varied.  

vii. 18m+ residential buildings requiring remediation due to the presence of unsafe non-ACM cladding that are being remediated by social housing landlords.  

• In the central estimate: a small uplift is made to the number of buildings that are known to require remediation in this category based on recent variance in data returns from social housing providers, and adjustments are made based on social housing providers’ intent to apply for government funding for remediation.  

• In the lower and upper estimates: these assumptions made for the central estimate are varied.  

• The assumptions on further buildings applying for funding are based on funding eligibility criteria at the time the estimates were made. 

viii. 18m+ residential buildings requiring remediation due to the presence of unsafe non-ACM cladding that are being remediated by individual responsible entities in the private sector i.e. private sector landlords.  

• In the central estimate: an assumption is made about the proportion of buildings that have been remediated by a private sector landlord without applying to government funded remediation programmes. This assumed proportion is applied to the number of buildings entering the Building Safety Fund and 18m+ Cladding Safety Scheme.  

• In the lower and upper estimates: the assumption made for the central estimate is applied to the lower and upper estimates for the Building Safety Fund and 18m+ Cladding Safety Scheme.  

MHCLG expects that the number of 18m+ buildings where remediation is required and monitored will mainly grow as a result of:   

• Buildings newly applying for the  Cladding Safety Scheme, and  

• Responsible entities conducting more assessments on their stock and identifying further buildings requiring remediation.  

For categories i. to v., and vii., the range between the upper and lower estimates are narrow – reflecting the relative certainty of information we hold on buildings requiring remediation from the ACM,BSF and social housing schemes, and the anticipated small number of 18m+ buildings that haven’t yet but may apply to the CSS scheme. There is a larger range around categories vi. -  the number of 18m+ buildings that will require remediation via the developer remediation contract. This reflects the fact that at the time the estimates were made developers were still assessing their stock.

Data quality

Assessment of data quality

In 2015, the UK Statistics Authority (UKSA) published a regulatory standard for the quality assurance of administrative data. To assess the quality of the data provided for this release, the department has followed that standard.

The data used in this release is classified as Medium risk in terms of data collection process, with a High public profile. The publication of the Building Safety Programme data release can be considered high profile, as there is significant mainstream media interest following the Grenfell Tower fire. These statistics form the headline figures for the remediation of unsafe buildings in England and as such are critical to policy making. They are also frequently quoted in national and local media.

The data quality is considered a medium concern given that a large number of local authorities and housing associations are involved in the data collection process, with some local authorities, the Greater London Authority and Homes England acting as intermediaries in the data collection process.

The medium rating does not reflect the suitability of the data and quality of this data for the Building Safety Programme’s purposes, but rather that the quality assurance processes undertaken are more stringent compared to low-risk data. It should be taken into account that the data is collected from multiple sources.

The data collection involves more than 100 organisations, including local authorities and housing associations. The department does not have full oversight of local authorities’ systems and quality procedures; we provide clear guidance and documentation to them via the DELTA data collection system.

Risk Profile Matrix

Statistical Series	Administrative Source	Data Quality Concern	Public Interest	Matrix Classification
Building Safety Programme data release	Local authorities’ and housing associations’ individual data systems	Medium	High	Medium Risk [A2]

Operational context and administrative data collection

Figure 1 shows the statistical production process, quality assurance (QA) checks and engagement between housing associations, local authorities, responsible stakeholders, AtkinsRéalis, and MHCLG during the process.

Building-level data is reported to MHCLG by housing associations and local authorities via the DELTA data collection platform. The data is continually updated via DELTA submissions and engagement with housing associations and local authorities to reflect progress on the ground. The DELTA collection platform pre-populates forms so that housing associations and local authorities can update records without having to submit complete entries each time.

Since March 2020, buildings in the ACM remediation programme have received expert construction advice from the firm AtkinsRéalis. Through AtkinsRéalis’ engagement with responsible entities, data is collected on remediation progress and reported to MHCLG. 

Waking Watch Relief Fund and Waking Watch Replacement Fund data is provided by applicants, with some local authorities administering the funds. MHCLG does not have full oversight of their systems and quality procedures. Guidance and documentation is available throughout the application process. Although some data cleaning took place to exclude duplicate applications and outliers for Waking Watch costs, the data provided was not subject to additional quality assurance. Data providers were not, for example, contacted for clarifications and corrections unless necessary for assessing the eligibility of the application.

In June and July 2020 responsible entities provided registration information to MHCLG through a Survey Monkey form, registering interest in applying for funding through the Building Safety Fund. These buildings were assessed by MHCLG for eligibility for funding. If eligible these buildings were handed to the relevant delivery partner (Homes England or Greater London Authority) to engage with responsible entities, data is collected on remediation progress and reported to MHCLG.

In March 2022 enforcement data began to be collected by MHCLG from and local authorities via the DELTA data collection platform. The data is continually updated via DELTA submissions and engagement with housing associations and local authorities to reflect progress on the ground.

Data on the application progress and remediation progress in the Cladding Safety Fund is provided by Homes England, the delivery partner, taken from their management reporting system. Homes England provide MHCLG with monthly data packs and data cuts as at the last working day of each month.

Developer statistics data are provided by developers who have signed the contract (some developers are not legally obligated to provide data, for example if they recently signed the contract and are within their deadline or they have no buildings which fall within scope of the contract). MHCLG provides the developers with a form with guidance throughout and data validation fields to aid completion. Although some data cleaning was undertaken to exclude duplicate buildings, buildings agreed not in-scope with the developer and to ensure the data is in the correct format, the data provided was not subject to additional quality assurance. Developers were not, for example, contacted for clarifications and corrections unless necessary to confirm inclusion in the dataset.

The building level Fire Remediation Survey of Social Housing in England is collected and administered by the Regulator for Social Housing on behalf of MHCLG. MHCLG provide clear guidance and documentation to complete the survey to RPs via the NROSH data collection system. The collection form contains validation checks to ensure logical consistency in the data returned. The data returns are then subject to a joint validation process between MHCLG and RSH to align the building-level and aggregate-level survey returns. The aggregate level results have been found to be broadly consistent with RSHs regulatory understanding of providers’ progress on remediation.

Data reported by social housing providers can change between quarters as improvements are made to the data collections definitions and guidance, and social housing providers’ understanding and adherence to these standards. For example, a fall in the number of buildings with cladding defects that have started or completed remediation between September and December 2024 and between December 2024 and March 2025 was driven by social housing providers making revisions to their data returns.     

Communication with data supply partners

MHCLG asks for updates to building-level data, especially remediation status, throughout each month and requests that housing associations and local authorities submit important updates before the data cut-off point (the last day of each month). Building owners, managers and agents report the remediation status of a building periodically. AtkinsRéalis provide regular updates on remediation progress, with all changes throughout the month reported to MHCLG at the end of the month. Delivery partners for the Social Sector ACM Remediation Fund, the Private Sector ACM Remediation Fund, BSF Remediation Fund and Cladding Safety Scheme also provide updates to MHCLG, with weekly updates.

There is a risk that some housing associations and local authorities have provided postcodes that are no longer in use. If there are any differences between the data supplier’s responses and other data sources, MHCLG reconciles any differences and improves the data quality.

Figure 1: ACM Quality assurance flow diagram

Figure 2: BSF Quality assurance flow diagram

QA principles, standards and checks by data suppliers

For ACM housing associations and local authorities update DELTA to reflect progress in remediation and these updates are included in the dataset. Starts and completions for private sector residential buildings are confirmed by local authorities before it is updated in the dataset, and subsequently, the data release.

Completions in the ACM programmes are confirmed with a sign-off certificate from the relevant Building Control body, where necessary. Local authorities also confirm if a building is under 18 metres or the ACM cladding systems comply with Building Regulations, either of which would result in a building falling out of scope of this data collection and reporting.

For BSF Homes England, Greater London Authority and MHCLG Social Sector team provide updates to MHCLG to reflect progress in remediation and these updates are included in the dataset. For the CSS, Homes England provide similar updates. Starts and completions are confirmed by applicants via Delivery Partner Caseworkers before it is updated in the dataset, and subsequently, the data release. Completions are confirmed with a sign-off certificate from the relevant Building Control body, where necessary.

Produces’ QA investigation and documentation

When reviewing the dataset using updates from engagement or the DELTA collection system, a conflict checker is used to ensure there are no inconsistencies with previous data releases. MHCLG quality assures the building-level data (i.e. addresses/postcodes, tenure, dwellings, and remediation status) using other data sources such as the Energy Performance Certificates (EPC) database and Valuation Office Agency (VOA) data.

MHCLG have collected data on the number of dwellings from responsible stakeholders and where a response was not given, the Valuation Office Agency data is used. The VOA data is also used to validate the responses from responsible stakeholders with respect to the number of dwellings, as well as addresses and postcodes. In this Data Release there are two private sector buildings which are yet to be remediated for which we do not have an estimate of dwellings.

For some buildings there is a mismatch between the responses MHCLG received and the VOA data. Where we have data from both sources, the degree of match for private sector buildings is 42% (with 75 exact matches among the 179 buildings with data from both sources) and it is 76% for social sector buildings (111 of the 147 buildings). This results in a range of estimates for the numbers of dwellings in these sectors for both remediated and yet to be remediated buildings. Where the range is up to and including 300 dwellings, it is reported as a combined number. Otherwise, as in the case of private sector buildings – both remediated and yet to be remediated – we report the range. Where we do not yet have an estimate of dwellings, these are not included in calculating the range. For both sectors, where buildings are known to have vacated their residents, the dwellings estimates include the dwellings in these buildings unless stated otherwise. The rounded mid-point of the range is used for an approximate estimate of leasehold dwellings that will receive support through the ACM funds.

The VOA data was determined to be a suitable source to validate the number of dwellings based on quality assessment by the VOA and ONS as part of work on the 2021 Census. Every residential dwelling that is liable for Council tax has a record with the VOA, so the data has good coverage and accuracy. However, there is a slight degree of incompleteness. Property attribute data are only updated when it is brought to the attention of the VOA that a record may be inaccurate. Reliance is placed upon local authorities to flag any changes to the VOA (such as new builds, demolitions, or alterations). As a result, there are some records in the list that are not updated as regularly as others, and the time lag associated with these updates is unclear.

Once the data collection is locked down, two members of the Building Safety Programme data team begin working on updating the monthly data release. One takes the role as the lead producer and the other takes the role of quality assuring the data.

The lead statistician updates the data release, the second data team member then goes through the draft, quality assures the data and the accompanying published data tables. Simultaneously, a Building Safety Programme team member external to the data team reviews and quality assures the release.

A quality assurance checklist, which evolves over time, is used by the second data team member to work through the draft once it is complete. The quality assurance checklist includes:

1. ensuring totals in the tables and figures align with the disaggregated data,
2. ensuring published figures across the data release are consistent,
3. checking for inconsistencies compared to any previous data releases,
4. ensuring the data release map is accurate,
5. performing checks related to disclosure so that any ACM clad buildings are not identified in areas with fewer than ten high-rise buildings, and
6. making sure all changes in the data are plausible.

Once the data team are content that the items on the checklist have been scrutinised and ticked off, the provisional Data Release is sent to senior staff for approval. Once approved by senior staff, the Data Release is prepared for publication.

Definitions

Building control: A statutory process of assessing plans for building work and building work on site to decide whether the plans and work comply with the requirements in Building Regulations.

Building Inspections: an inspection performed under the Housing Act 2004’s Housing Health and Safety Rating System by a building inspector usually an environmental health officer of a local authority or by the fire rescue service.

Building Safety Fund (BSF) 2020: The fund for remediation of unsafe non-ACM cladding systems on residential buildings 18 metres and over in both the private and social residential housing sectors that opened was open in June and July 2020. The fund addressed fire safety risks caused by unsafe non-ACM cladding systems. These were buildings with cladding materials and systems that do not meet an appropriate standard of fire safety and could pose a significant risk to the health and safety of residents. If a building met the eligibility criteria it would then be fully remediated. When the BSF reopened in 2022 if an application had not already received its Funding Application Board approval or works had not started on site the responsible entity could submit a Fire Risk Appraisal of the External Wall System (FRAEW) and be newly assessed under the new criteria.

Building Safety Fund (BSF) 2022: The BSF reopened in 2022 with new eligibility criteria, to address life safety risks associated with cladding on high-rise residential buildings. New guidance was published, PAS9980:2022, which provided a clear and proportionate methodology for the Fire Risk Appraisal of the External Wall System (FRAEW). In order to complete an application responsible entities are required to submit an application and send a corresponding FRAEW to MHCLG (or Homes England via the Cladding Safety Scheme from April 2024). To meet eligibility buildings need to be above 18m (with 30cm tolerance), have at least one qualifying residential leaseholder, cladding as defined in the PAS 9980:2022 and have a FRAEW which recommends action to address life safety fire risks. The FRAEW can recommend mitigation, partial or full remediation. If a building started remediation after 11 March 2020 but before 28 July 2022 and  have not completed remediation they can still apply under BSF 2022 but under the original criteria.

BS8414: BS8414 is a British standard test method that measures the fire performance of external cladding systems.

Consolidated Advice Note (CAN): The CAN is the original criteria for registrations to the BSF 2020. This was used to determine eligibility for these buildings,  MHCLG made technical assessments based on the height of the building and an assessment of the non-ACM cladding system.

Care Quality Commission (CQC): The Care Quality Commission (CQC) is an executive non-departmental public body, sponsored by the Department of Health and Social Care. It regulates all health and social care services in England.

Category 1 rating: where a risk is deemed to be category 1, a local authority has a duty to take enforcement action.

Category 2 rating: where a risk is deemed to be category 2, an authority has the power to take action.

Cladding Safety Scheme: The fund for remediation of medium-rise (11 – 18 metres in height) residential buildings with cladding defects in England and high-rise residential buildings outside of London with non-ACM cladding systems, that was fully launched in July 2023. Delivered by Homes England.

Crown building: a building in which there is a Crown interest or a Duchy interest

Dwelling: A self-contained unit of accommodation which may comprise one or more household spaces (a household space is the accommodation used or available for use by an individual household). This definition of a dwelling is consistent with the Census 2011.

Energy Performance Certificates (EPC) data: The EPC database is open data that records the energy performance of dwellings as well as other dwelling-level variables such as floor level, tenure, and street address/postcode.

Enforcement Action: is where an inspection under the Housing Act 2004’s Housing Health and Safety Rating System has been organised/undertaken and includes where a statutory notice has also then been served.

Fire Risk Assessment of External Walls (FRAEW): An assessment to inform the Fire Risk Assessment of the building, it should identify, for all wall systems, the level of risk posed and set out an overall assessment of the risk rating. It should consider the range of possible remedial measures available, including mitigation measures and set out clear recommendations on proposed actions and justifications for this choice. As part of an application to the BSF applicants are required to submit a FRAEW following the methodology set out in PAS9980:2022 to determine the buildings eligibility. A FRAEW is applicable where the risk is known, or suspected, to arise from the form of construction used for the external wall build-up, such as the presence of combustible materials.

Fire Safety Assessment (FSA): within the developer remediation contract this means an assessment of fire-safety risks carried out in accordance with the Standard, the Type, scope and objectives of which are such as to enable the identification of all actual and suspected Defects, which may include a fire risk assessment carried out in accordance with the Fire Safety Order (as amended, updated or supplemented from time to time) that meets the foregoing requirements.

Houses in Multiple Occupation (HMO): A building, or part of a building, consisting of one or more units of living accommodation that is not a self-contained flat or flats. The living accommodation must be occupied by more than one household who share one or more of the basic amenities (toilet, washing facilities and cooking facilities). This definition of HMO is consistent with the standard test. As defined by local authorities in the data provide by the Ordnance Survey ®.

Housing Health and Safety Rating System (HHSRS): is a risk-based assessment evaluation tool to help local authorities identify and protect against potential risks and hazards to health and safety from any deficiencies identified in residential premises. Each hazard has a weighting which will help determine whether the building is rated as having risks which are either category 1 or category 2.

Joint Inspection Team (JIT): was set up by the department, and is hosted by the Local Government Association, to provide expert advice to local authorities on enforcement on buildings with unsafe cladding.

Life-critical fire-safety defect: taken to mean defects, shrinkages, faults or other failings (on their own or in  conjunction with other defects, shrinkages, faults or failings) in a building, which give rise to fire safety risks which are assessed as not “medium - tolerable” (or better) by a FRAEW undertaken in accordance with PAS 9980 (in relation to external wall construction or cladding) or assessed as high risk or medium risk by an equivalent FRA according to industry standards covering other parts of the building.

Litigation action: Legal proceedings to recover costs from those responsible for installing the unsafe cladding.

Ordnance Survey ® (OS ®): Ordnance Survey ® (OS ®) is Great Britain’s national mapping agency. It carries out the official surveying of Great Britain, providing accurate and up-to-date geographic data.

PAS 9980:2022: This is a code of practice which sets out a method for competent professionals to conduct FRAEW’s for existing multi-storey, multi-occupied residential buildings.

Private sector residential building: A building is classified as a private sector residential building if the freeholder is a private company and contains at least one dwelling occupied as private residential accommodation. Private sector residential buildings exclude hotels and student accommodation.

Publicly owned buildings: A publicly owned building is one that is owned by a public authority, a government department or an arms-length body.

ReIHMax: RelHMax is a measurement from the base of a building to the top of the tallest roof structure (e.g. a chimney stack).

ReIH2: ReIH2 is a measurement from the base of a building to the tallest eave height.

Residential Education: A building is classified as a residential education if the tenancy specifically states that it must be let exclusively for the purposes of boarding school accommodation and halls of residence, as defined by local authorities in the data provide by the Ordnance Survey ®.

Sheltered accommodation: Buildings are classified as sheltered accommodation if made available exclusively to the elderly, disabled and vulnerable people, as defined by local authorities in the data provide by the Ordnance Survey ®.         

Social sector financial viability claim in the BSF: Social sector buildings, where the freeholder is a registered provider of social housing and the building is used for housing social tenant, can submit a financial viability claim to receive 100% of their BSF funding from the government. To receive 100% of funding, the freeholder must undergo various financial viability processes set out by MHCLG.

Social sector residential (leaseholder) building in the BSF: A building is classified as a social sector residential (leaseholder) building in the BSF if the freeholder is a registered provider of social housing and there is at least one resident with a qualifying lease living in the building and the building is used for social housing. Social sector residential (leaseholder) buildings only receive partial funding for their works, dependent on the number of eligible leaseholders who pay a service charge.

Social sector residential building: A building is classified as a social sector residential building if the freeholder is a registered social landlord and there is at least one social tenant living in the building.

Statutory Notices: a formal notice served by an authority under the Housing Act (2004) in response to a category 1 or category 2 hazard.

Student accommodation: Buildings are classified as student accommodation if the tenancy specifically states that it must be let exclusively to students.

Topographic Identifier (TOID): A topographic identifier is a unique and persistent identifier used to uniquely identify real world objects by the Ordnance Survey ®.

Valuation Office Agency (VOA) data: The Valuation Office Agency (VOA) is responsible for banding properties for Council Tax and it is a statutory requirement of the VOA to maintain accurate valuation lists for Council Tax. The VOA’s Property Details dataset contains information on the main features and attributes of a property including the address/postcode and number of dwellings.

Unique Property Reference Number (UPRN):  The UPRN is a unique identifier available for each address recorded within the AddressBase ® data.

Revisions policy

The revisions policy has been developed in accordance with the UK Statistics Authority’s Code of Practice for Statistics.

It covers two types of revisions that the policy covers, as follow:

Non-scheduled revisions

Where a substantial error has occurred as a result of the compilation, imputation or dissemination process, the statistical release, live tables and other accompanying releases will be updated with a correction notice as soon as is practical.

Scheduled revisions

Where new information becomes available post publication, this is incorporated into the next scheduled Data Release, data tables and any other accompanying documents.

Other information

Uses of the data

The data in this release is used to help the Building Safety Programme make buildings safe and to make people feel safe from the risk of fire, now and in the future. Ministers and officials in the Ministry of Housing, Communities and Local Government use this information to understand progress with the remediation of buildings with ACM cladding systems unlikely to meet Building Regulations and to consider possible policy responses.

User engagement

Users are encouraged to provide feedback on how these statistics are used and how well they meet user needs. Comments on any issues relating to this statistical release are welcomed and encouraged. Responses should be sent to BuildingSafetyData2@communities.gov.uk.

Read the Department’s engagement strategy to meet the needs of statistics users.

Voluntary compliance with the Code of Practice for Statistics

The Code of Practice for Statistics was published in February 2018 to set standards for organisations in producing and publishing official statistics and ensure that statistics serve the public good.

Whilst the statistics in MHCLG’s Building Safety Programme Data Release have been designated as management information rather than ‘official statistics’, the principles of transparency of high-quality analytical outputs to inform decision making and the public underpin this data release. In October 2020, the Building Safety Programme Data Release was awarded the Office for Statistics Regulation’s (OSR) first Voluntary Application of the Code Award.

Trustworthiness: trusted people, processes and analysis

Honesty and integrity (T1): The Building Safety Programme Data Release is managed by professional analysts in MHCLG – this involves design of data collection tools, checking of provided data, and analysis. Waking Watch Relief Fund analysis is overseen and quality assured by professionally qualified analysts. Building Safety Fund analysis is overseen and quality assured by professionally qualified analysts. All other work is undertaken by professionally qualified and experienced data analysts - professional members of the Government Statistical Service, Government Operational Research Service or Government Social Research profession, where all staff have Personal Development Plans focussed on their long-term professional development (Professional capability – T5).  

Independent decision making and leadership (T2): The work is governed by the Analysis and Data Directorate in MHCLG, accountable to MHCLG’s Chief Analyst and the Head of Profession for Statistics.  

Orderly release (T3): MHCLG pre-announces the publication date for this data release. As part of our continuous improvement, the data cut-off date for data releases aligns to the end of the calendar month or for BSF the last appropriate Thursday. 

Transparent processes and management (T4)*: MHCLG has robust, transparent, data-management processes.  

All ACM remediation data are provided by local authorities, housing associations, building owners / developers / managing agents, the DHSC, DfE and the BRE. Responsibility for the data lies with the data provider - as such only data either provided by BRE following testing or data verified by local authorities, housing associations, the DHSC or DfE are published. 

All BSF remediation data are provided by building owners/developers/managing agents along with delivery partners (GLA, HE and Social Sector). Responsibility for the data lies with the data provider – as such only data provided by delivery partners is published. 

Data Governance (T6): MHCLG uses robust data collection and release processes to ensure data confidentiality. For data on ACM remediation a published privacy notice clearly sets out why data are collected, data sharing, and the legal basis for processing data. For Waking Watch Relief Fund data the privacy notice clearly sets out to WWRF applicants how and why MHCLG use personal information and their rights and responsibilities. This is consistent with the General Data Protection Regulation. 

For data on BSF remediation a published privacy notice clearly sets out why data are collected, data sharing and the legal basis for processing data.

High quality: robust data, methods and processes

Suitable data sources (Q1): Data originates from a number of sources outside the control of MHCLG: local authorities, local Fire and Rescue Services, housing associations, building owners / developers / managing agents, DHSC, DfE, and BRE. Data are triangulated, where possible, and data are always verified by these bodies – who are ultimately responsible for the quality of their data. Where the quality of data is unclear, it is either not published or quality issues are highlighted. 

All data collections which have contributed to the analysis of buildings between 11 metres and 18 metres and buildings at least seven storeys but under 18 metres tall have been provided by the Ordnance Survey ® (OS ®) and Energy Performance Certificates (EPC). Responsibility for the data lies with the data provider.  

Sound methods (Q2): Data collection tools and processes are robustly designed and tested prior to use, learning lessons from previous Building Safety Programme data collections and best practice from across the government analytical community. 

Assured Quality (Q3): All data are quality-assured prior to publication.  

As the quality of data improves, it is our intention to publish further data on the safety of high-rise and complex buildings. Information to date on data improvements and new content added to the data release is outlined in the Data Collection section of the Technical Note.  

For transparency, we published the Building Safety data tables for the first time in the November 2018 data release.  

A revisions policy is in place to ensure that any revisions are addressed quickly and systematically.

Public value: supporting society’s need for information and accessible to all

Relevance to users (V1): The nature of building safety means this data release is of high value to the public, to residents of high-rise buildings and building owners/developers. However, the data release balances disclosure control (risks of disclosing individual buildings) with informing the public and keeping people safe. 

Periodically, new data are added to the data release once we are content with the quality. Data are also removed if they do not add to understanding of building safety or are superseded by other data in the data release. Where a proposal is made to remove data, this is flagged in the data release with a period of one month given for users to express an interest. User views are then taken into account before final decisions are taken on removing data.  

Accessibility (V2): Given the immediate nature of building-safety issues, and the need to develop interim solutions and longer-term remediation, data are shared with Fire and Rescue Services and Local Authorities once MHCLG are aware of issues.  

Officials and Ministers also use the data prior to publication to monitor progress and develop timely interventions. This enables immediate action to be taken. Therefore, the data may be used for operational purposes before publication in this data release.  

To assist with public accessibility the data tables underpinning this data release are published as HTML, as well as being available as .csv files. Since the November 2020 release, the data release and Technical Note have been published using an improved accessible template.  

Clarity and Insight (V3): Complex data are clearly explained in the data release and accompanying Technical Note. Where insight and interpretation are offered, these have been verified with local authorities, BRE and other knowledgeable bodies.

Innovation and improvement (V4): This data release series started in December 2017. As the quality of data improves, it is our intention to publish further data on the safety of high-rise and complex buildings. Information to date on data improvements and new content added to the data release is outlined in the Data Collection section of the Technical Note. 

Efficiency and proportionality (V5): Burdens on data providers have been considered, and MHCLG has worked to minimise the burden. Given the nature of building safety, MHCLG feels the current burden on data providers is appropriate.  

Given issues of public safety, only aggregate level data are published. Hence, further analysis of primary data is not possible.