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Reinforced autoclaved aerated concrete (RAAC) is a lightweight ‘bubbly’ (ie ‘aerated’) form of concrete. It was mainly used in flat roofs in the UK from the mid-1950s to the mid-1990s. Whilst it exists in buildings in both the public and private sectors, it is more prevalent in schools, hospitals and public buildings. RAAC was seen as a cheaper and easier alternative to concrete. However, it is less durable and, typically has a lifespan of around 30 years. There is a risk it can fail and lead to structural collapse. This has jolted the government into action to mitigate the dangers.

Few people could have missed the news in late 2023 when RAAC hit the headlines, but what is the current situation? And what is being done to the buildings that are affected?


On 8 February 2024, the government confirmed plans to permanently remove RAAC from all schools and colleges in England. It also advised that all work to remove RAAC will be funded through grants or the School Rebuilding Programme. There are over 22,000 schools and colleges in England. From those, 234 have confirmed RAAC so far. The DfE has indicated that 119 of these schools will need one or more buildings rebuilt or refurbished. There are 110 schools and colleges where work to remove RAAC will be less complex and extensive. A further 5 educational institutions have alternative arrangements in place.


The NHS in England put in place a rolling programme to identify RAAC in hospitals after the RAAC alert issued by The Standing Committee on Structural Safety (SCOSS) in 2019. As of 17 October 2023, there are 42 hospital sites with confirmed RAAC in the programme. The Department of Health and Social Care states that the programme is backed with significant additional funding of £698 million from 2021 to 2025 for trusts to put in place necessary remediation and failsafe measures.

What you need to do if you suspect RAAC?

The first thing you need to do is arrange for a survey of the building to determine whether RAAC is present. At Chawton Hill, the team have been carrying out widespread surveys to identify RAAC. If RAAC is found, we can help find an engineer to come and assess its severity and identify the next steps. In the event it is deemed low risk, then it will just need monitoring. If it is more serious, then remedial action might be needed, and work may need to be carried out. Kit Lu has been particularly busy helping our clients with their concerns. We’re always happy to help where we can.

Considerations and costs

The remedial works that need to be done will vary from building to building and depend on a variety of factors. These include building size, location, and use. This will then have an impact on how long the work will take and the cost. It is also important to consider the implications for the people who use the building. Whether it’s residents in a house, patients in a hospital or students at a school.

If substantial structural work needs to be done – e.g. a whole new roof deck, then the building may be out of action. It can be difficult to arrange work around school times. We can help with scheduling, to identify the most efficient and least disruptive time to schedule any works.

There’s also the added risk of encountering other harmful materials such as asbestos. Again, Chawton Hill have several trusted suppliers who we can draw. This will help minimise risk and ensure everything is done to ensure safety and legality when tackling such issues.

It’s important to consider the legal implications too. The public sector has received a lot of attention but the prevalence of RAAC in the private sector should not be overlooked or underestimated. The Defective Premises Act 1972 imposes a duty of care on landlords and constructors. It would be advisable for a building owner or operator of a property built between 1950s and 1990s to organise a survey if they suspect RAAC could be present.

If you have any concerns or questions or would like to arrange a survey then please don’t hesitate to get in touch with one of the team today.