Government investigation into concerns regarding lightweight concrete

This article was co-authored by Bushra Jalil, Trainee Solicitor, London.

Update - 1 September 2023 – The UK Government has issued further guidance for responsible bodies of state funded education estates in England which have a confirmed or suspected presence of reinforced autoclaved aerated concrete (RAAC).

Since 2022, the Department of Education has been asking schools to provide information by way of a questionnaire and survey of the site if RAAC is suspected to help the Government understand the presence of RAAC across schools which form part of the Government estate.

  • 156 schools so far have been found to contain RAAC, of which 52 have been supported to have mitigations put in place, such as repair works.
  • 104 - which have been contacted by the Government this week - have no mitigations in place and require urgent action by way of vacating the spaces or buildings which are known to contain RAAC.
  • The UK Government has contacted those who will need to close immediately if appropriate mitigating measures are not in place. More schools may be affected as not all building surveys have been completed.

The updated government-issued guidance for schools advises responsible bodies to vacate and restrict access to spaces with confirmed RAAC and that these spaces should remain out of use until appropriate mitigations are in place. The guidance covers the management of RAAC in the estate, including working with an allocated Department of Education caseworker if affected, and managing the impact of closure on education.

The Government has recently announced that it is launching a UK Government-wide inquiry into the use of reinforced autoclaved aerated concrete (RAAC) across the entire Government estate.

This announcement comes amidst previous inquiries which focused predominantly on school buildings, following the collapse of a roof in a school in Kent in 2018. Each Whitehall department is to now assign a civil servant to identify the use of RAAC across the entire Government estate. This wider expansion across other public buildings demonstrates a renewed urgency in cracking down on this given the serious safety concerns which have been identified.

RAAC is a type of material which significantly differs from traditional reinforced concrete. A number of issues have been identified with it but notably it is a lightweight version of traditional concrete which is much weaker due to the way in which it was made. It is aerated which makes it look bubbly and contains no ‘coarse’ aggregate, making it less dense than traditional concrete.

RAAC panels were commonly used in schools, colleges and other building constructions from the 1950s until the mid-1990s, and its life span is estimated at 30 years. Hence, many RAAC structures are now well past their shelf life. The recognised structural deficiencies in these panels brings a risk of structural failure and sudden collapse.

Many schools have already been identified as being at risk of collapse, but some are still yet to carry out surveys to check for the presence of RAAC. A review was also held last year into several hospitals considered at risk, and in March of this year, a report published by NHS Providers (an organisation representing NHS Trusts) urged the Government to expediate the process of replacing unsafe RAAC planks and provide the necessary funding to replace these structures. The report noted that there are currently 14 hospitals with RAAC planks which will require extensive building works to prevent their closure, demonstrating a significant risk to patient lives.

The Department of Education published non statutory guidance in December 2022 to help Responsible Bodies (which include trusts and councils) to identify and manage RAAC in educational buildings. The guidance provides a detailed step by step approach to assessing, investigating and developing a RAAC management and remediation strategy. Steps include information collection on RAAC (including familiarisation with existing guidance), an initial assessment, the appointment of a specialist engineer once RAAC has been identified or suspected, a detailed assessment followed by a management and remediation strategy. The announcement of the inquiry into the entire Government estate has come recently, and it may be that similar guidance (if not a replica of that already issued) will be published for this to reflect the expansion beyond schools.

Implications for Insurers

A sudden failure of RAAC panels in roofs, floors, walls and cladding systems is a real risk attracting serious consequences to those present on the affected premises and is likely to put insureds in breach of the Health and Safety regulations. This is therefore likely to be a key coverage consideration for Insurers . The unpredictability of collapse adds to the risk, and Insurers will want their Insured to take proactive measures to mitigate this risk by undertaking investigations to identify the presence of RAAC panels and taking steps to remedy this accordingly. Insurers will welcome the announcement that the entire Government estate is now to be considered, which will hopefully expediate the process in urgently identifying these risks across the board.


The announcement of the inquiry into RAAC to cover the entire Government estate has come recently, and Insurers will want to keep a close eye on what the findings of this will be, or if any further guidance is issued as a result. We will be able to provide a further update once this become clearer.

Related item: RAAC and its impact upon construction professional indemnity claims

Read other items in London Market Brief – September 2023

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