On 1 February 2024, the House of Lords is scheduled to consider the following question for short debate:

Lord Addington (Liberal Democrat) to ask His Majesty’s Government how they plan to mitigate the safety risks of reinforced autoclaved aerated concrete in schools and to ensure the swift deployment of financial assistance for necessary maintenance and construction upgrades.

1. What is RAAC?

Reinforced autoclaved aerated concrete (RAAC) is a lightweight construction material used in buildings between the mid-1950s and mid-1990s.[1] The Royal Society of Chemistry explains that standard concrete is usually made from cement, sand, aggregate and water. RAAC is a mix of cement, calcium hydroxide, fine sand and aluminium powder. The aluminium and calcium hydroxide react, ultimately creating ‘bubbles’ that make up 65–85% of the material’s volume. It is cured under heat and pressure and reinforced with bars (usually steel rebar) to make it suitable for load bearing. It is usually coated with waterproofing made from bitumen or latex.[2]

RAAC is light, cheap and easy to mould into panels, and provides better thermal insulation than traditional concrete. However, RAAC is easily corroded following water ingress.[3] RAAC’s aeration and lack of coarse aggregate mean it does not bond as well as traditional concrete to its reinforcements. Cracks can form, which weaken panels, leading to failures with little warning. Its useful life is estimated to be around 30 years.[4] However, the Royal Institute of Chartered Surveyors (RICS) emphasises that lifespans are affected by many factors, including whether buildings are well maintained and whether original design factors, such as estimated load weights, stay the same.[5]

In the UK, RAAC has been used in a range of settings, including the construction of schools, hospitals, courts and private buildings.

2. Concerns about RAAC

The Standing Committee on Structural Safety has noted that “many incidences” of RAAC failures were recorded in the 1980s, predominately from roof planks installed in the 1960s.[6] Indeed, production of RAAC in the UK ceased in 1982 due to concerns over its structural performance and life expectancy.[7]

In 1996 the Building Research Establishment (BRE) published a report noting excessive bending, sagging, corrosion and cracking in RAAC roof planks.[8] The BRE recommended annual inspections for RAAC panels in poor condition, and inspections every five years for panels in good condition.[9] In 2002, BRE reported again, warning that:

  • coatings over 20 years old had likely been compromised
  • corrosion could occur without visible signs of poor panel condition, posing a risk of collapse without warning in panels over 20 years old
  • some panels did not meet regulations when initially installed[10]

3. RAAC failures in schools

In 2018 a roof at Singlewell Primary School in Kent constructed using RAAC collapsed without warning.[11] Following this, the Local Government Association (LGA) and Department for Education (DfE) contacted all bodies responsible for school buildings advising them “as a matter of urgency” to check whether their buildings had roofs, floors, cladding or walls made from RAAC.[12]

Guidance from the DfE stated that if RAAC is suspected a qualified building surveyor or engineer should be appointed and the DfE should be informed.[13]

The Institution of Structural Engineers has also suggested a range of measures that might need to be put in place to mitigate against the failure of RAAC, depending on the findings of condition surveys, from monitoring, propping and reinforcement to the removal and replacement of panels or entire roofs.[14]

In 2022, the DfE sent a questionnaire to responsible bodies asking for information about the potential presence of RAAC across school estates.[15]

The failure of RAAC panels in three school buildings in the summer of 2023 led to the DfE advising a “risk-averse approach” in schools. As Jane Cunliffe, DfE chief operating officer, stated in oral evidence to the Public Accounts Committee (PAC) in September 2023, “all spaces with RAAC should be closed”.[16] The advice was issued just before the start of the autumn term, leading to some schools adopting virtual learning and/or temporary classrooms, and to 19 schools delaying the start of term.[17]

4. How many schools have RAAC?

The most recently published DfE statistics from November 2023 confirmed the presence of RAAC in 231 education settings (publicly funded schools and colleges) in England.[18] At the time of publication, all pupils were in face-to-face education in 228 of those settings. The government has since confirmed that two further schools have returned to full in-person teaching, with one still employing some remote teaching.[19]

5. Mitigating risks and providing funding

In a DfE blog on 6 December 2023, the government said that all settings known to contain RAAC would be assigned to a dedicated caseworker to assist with “individual solutions”.[20] These solutions included safety measures in the affected areas and erecting temporary classrooms. The blog stated that funding would be available for these immediate mitigations.[21]

The government also committed to funding “all reasonable requests” for additional costs including transporting pupils to other locations and temporarily renting local halls.[22]

The DfE states that it has invested “over £15bn since 2015 to keep schools in good working order, including £1.8bn for 2023–24”.[23] In a statement, Secretary of State for Education Gillian Keegan also said that the government is funding longer-term refurbishment or rebuilding projects to address the presence of RAAC:

Schools and colleges will either be offered capital grants to fund refurbishment work to permanently remove RAAC, or rebuilding projects where these are needed, including through the school rebuilding programme.[24]

The school rebuilding programme was announced in June 2020, with the aim of 500 schools benefitting from major building or refurbishment projects across the decade.[25] The PAC has highlighted delays in the programme, which the DfE attributed to inflationary pressures in the building industry.[26] The DfE said it has amended its funding policies to a model where risks are shared between the government and the developer to manage cost pressures and improve the speed of delivery.[27]

The PAC also noted the difference between the DfE’s spending review 2020 figures and ultimate allocation. The DfE recommended £5.3bn a year in capital funding to maintain schools and mitigate the most serious risks of building failure. The Treasury allocated an average of £3.1bn a year.[28] The committee concluded that the DfE therefore focused on reactive measures, responding to immediate structural and safety issues, failing to account for long term value for money considerations of rebuilding schools whose condition was generally deteriorating.[29]

In addition, the PAC called on the DfE to set eradication date targets for RAAC.[30] The committee suggests following the approach of the Department of Health and Social Care, which has committed to eradicating RAAC across the NHS estate by 2035.[31]

Similarly, a National Audit Office (NAO) report on the condition of school buildings in 2023 also called for the DfE to “determine by when, and through what means, it plans to have fully dealt with RAAC as a safety issue across the school estate so that it is no longer a critical risk”.[32]

The NAO report also highlighted a lack of information on the condition of school buildings. In September 2023, members of the House of Lords voted to add an amendment to the Levelling-up and Regeneration Bill which would have required the government to establish a register of schools and hospitals in England in “serious disrepair”.[33] The amendment was rejected by the House of Commons during ping-pong of the bill, however, and thus did not ultimately form part of the subsequent act.[34]

The government has also said that it has asked organisations which award qualifications to “be as flexible as possible in agreeing longer extensions for coursework and non-examined assessment” for pupils impacted by RAAC.[35]

6. Views from the education sector

On 7 September 2023, six education unions wrote to the secretary of state for education arguing that if the government did not increase funding for the school rebuilding programme, the RAAC problem would not be resolved until the 2030s.[36] Similarly to the NAO and PAC, they pushed for a deadline for RAAC to be cleared from every school.

Also on 25 September 2023, eight education unions, including the six from the previous letter, wrote to the prime minister arguing in their view that, due to chronic underfunding and lack of maintenance, some school sites posed a “risk to life”.[37] They called on the government to invest “at least an extra £4.4bn annually” in building upgrades, and advocated for the creation of a national register of all schools with RAC and asbestos.

The Association of School and College Leaders (ASCL) has said that parents are increasingly removing their children from schools affected by RAAC. Concerns cited by parents included lack of access to specialist classrooms like science labs. The ASCL has called for a new “recovery funding stream” to help students with lost or impacted learning catch up.[38]

7. Read more

Cover image by MChe Lee on Unsplash.


  1. Maria Burke, ‘Understanding chemistry at play in RAAC explains weakening of concrete—and how to slow it down’, Chemistry World, 8 September 2023. Return to text
  2. As above. Return to text
  3. HSE People, ‘What is RAAC concrete and why is it a safety risk?’ accessed 24 January 2024. Return to text
  4. Standing Committee on Structural Safety, ‘Failure of reinforced autoclaved aerated concrete (RAAC) planks’, May 2019. Return to text
  5. Royal Institute of Chartered Surveyors, ‘RAAC: Advice and FAQs’, 26 January 2024. Return to text
  6. Standing Committee on Structural Safety, ‘Failure of reinforced autoclaved aerated concrete (RAAC) planks’, May 2019. Return to text
  7. Trevor Rushton, ‘Identifying problematic RAAC planks’, Built Environment Journal, 21 November 2019. Return to text
  8. HSE People, ‘What is RAAC concrete and why is it a safety risk?’ accessed 24 January 2024. Return to text
  9. As above. Return to text
  10. As above. Return to text
  11. Alexander Butler, ‘The RAAC concrete ‘ticking time bomb’ that schools were warned about years ago’, Independent, 2 September 2023. Return to text
  12. Local Government Association, ‘Information on reinforced autoclaved aerated concrete (RAAC)’, accessed 24 January 2024. Return to text
  13. Department for Education, ‘Reinforced autoclaved aerated concrete: Identification guidance’, 19 September 2023. Return to text
  14. Institution of Structural Engineers, ‘Reinforced autoclaved aerated concrete (RAAC) panels: Investigation and assessment’, 7 March 2022. Return to text
  15. Department for Education, ‘List of schools affected by RAAC and what you need to know about the new guidance’, updated 6 December 2023. Return to text
  16. Public Accounts Committee, ‘Oral evidence: The condition of school buildings’, 11 September 2023, HC 1338 of session 2022–23, Q108–207. Return to text
  17. As above. Return to text
  18. Department for Education, ‘Reinforced autoclaved aerated concrete (RAAC): Management information’, 6 December 2023. Return to text
  19. House of Commons, ‘Written question: Schools: Concrete (7871)’, 11 January 2024. Return to text
  20. Department for Education, ‘List of schools affected by RAAC and what you need to know about the new guidance’, updated 6 December 2023. Return to text
  21. As above. Return to text
  22. House of Commons, ‘Written statement: Schools and colleges update (HCWS98)’, 6 December 2023. Return to text
  23. Department for Education, ‘List of schools affected by RAAC and what you need to know about the new guidance’, updated 6 December 2023. Return to text
  24. House of Commons, ‘Written statement: Schools and colleges update (HCWS98)’, 6 December 2023. Return to text
  25. Department for Education, ‘What is the school rebuilding programme and how is it benefitting pupils?’, 13 July 2022. Return to text
  26. House of Commons Public Accounts Committee, ‘The condition of school buildings’, 19 November 2023, HC 78 of the session 2023–24, p 18. Return to text
  27. As above. Return to text
  28. As above, p 10. Return to text
  29. As above, p 7. Return to text
  30. As above, p 5. Return to text
  31. As above, pp 5 and 12. Return to text
  32. National Audit Office, ‘Condition of school buildings’, 28 June 2023, HC 1516 of session 2022–23, p 11. Return to text
  33. UK Parliament, ‘Levelling-up and Regeneration Act 2023: HL report stage—amendment 281’, accessed 24 January 2024. Return to text
  34. HC Hansard, 17 October 2023, cols 281–3. Return to text
  35. House of Commons, ‘Written question: Schools: Concrete (7869)’, 10 January 2024. Return to text
  36. National Education Union, ‘Six unions ask urgent questions of Gillian Keegan about RAAC-affected schools’, 7 September 2023. Return to text
  37. National Association of Head Teachers, ‘Eight unions and the NGA call on the prime minister to invest £4.4bn+ per year to get a grip on the school buildings crisis’, 25 September 2023. Return to text
  38. Association of School and College Leaders, ‘Spring budget 2024 representation’, 24 January 2024. Return to text