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Explains how RAAC has been used in Wales and the work being done to manage buildings with RAAC.

First published:
8 September 2023
Last updated:

What is RAAC

Reinforced Autoclaved Aerated Concrete is a form of lightweight concrete used in construction in many buildings between the 1950s and 1990s.

RAAC is highly aerated with different material properties to conventional concrete.It is mainly found in roofs, occasionally in floors and walls. Visually, RAAC planks may look the same as pre-cast concrete, and may be hidden above false ceilings. Read a more detailed explanation from The Institution of Structural Engineers.

Its presence has been confirmed in a range of public sector properties including schools and hospitals across the United Kingdom.

How long has the government been aware of this issue?

UK governments have been aware of some of the vulnerabilities of RAAC since the 1990s.

The Welsh Government has been working with the UK Government and other devolved governments since 2018 to consider the potential management implications for buildings with RAAC.

In May 2019, an alert from the Standing Committee on Structural Safety (SCOSS) (an independent UK body) highlighted significant concerns about the structural safety of properties with RAAC.

A series of Welsh Government Ministerial statements on RAAC were made after the UK Government (Department for Education) shared its new evidence on 3 September 2023:

How have we been monitoring and managing public sector buildings with RAAC

The Welsh Government has been working with the UK Government and other devolved governments since 2018 to consider the potential management implications for buildings with RAAC.

NHS organisations in Wales were notified about the risk of RAAC planks failing by the NHS Wales Shared Services Partnership (NWSSP) in November 2019. They were required to review all their buildings to see if any contained RAAC. Once the reviews were completed, a specialist structural engineer was appointed in November 2022, to review the reports and the locations where RAAC had been identified.

In February 2023, a further notice was issued to the NHS, on the recommendation of the specialist structural engineer to provide further assurances to NWSSP and the Welsh Government. Work continues around the detailed assurance surveys and assessments.

Local authorities were made aware of the potential issue with RAAC through the Welsh Local Government Association (WLGA) in February 2020 after the safety alert was published by SCOSS in 2019.

Since March 2023, the Welsh Government has been working closely with local authorities and the WLGA. A number of local authorities have completed their school estate review and it is underway in others. Details of any instance or awareness of RAAC in schools will now be requested as part of the annual education data collection exercise which will be undertaken over the coming months.

In May 2023, the Welsh Government commissioned a condition and energy survey of all state-funded schools and colleges. This would highlight any structures suspected of containing RAAC for further inspection by specialist structural engineers.

What has happened since August 2023?

On 31 August 2023, the UK Department for Education said incidents had emerged about RAAC in education settings. UK Government Ministers said a number of incidents happened over the summer period which meant there was a higher safety risk.

In response, the Welsh Government has commissioned, and has requested other public sector building owners and/or estate owners and/or those responsible for managing premises, to commission urgent new surveys of public sector buildings, including schools.

The NHS is finalising its survey work across its estate.

What risk does Reinforced Autoclaved Aerated Concrete pose?

To fully understand the scope, the Welsh Government has been working with the wider public sector, including local authorities and NHS Wales, to review buildings and estates to identify any areas suspected of containing RAAC.

The risk associated with the presence of RAAC in public sector buildings is not a new issue in the construction sector and work has been underway over time in Wales to ensure that risks are managed and, where required, remedial work and mitigations have been put in place.

The Welsh Government has asked local authorities and other public bodies to assess the wider public estate for the presence of RAAC. It has also asked stock holding local authorities about the presence of RAAC in social housing. Registered Social Landlords have been asked to assess their stock via Community Housing Cymru.

Where does responsibility sit if RAAC is identified in any public sector owned building?

The building owner and/or estate owner and/or those responsible for managing premises are responsible for building safety and for the safety of employees, tenants, pupils and members of the public who use the estate.

The Defective Premises Act 1972 and subsequent Building Safety Act 2022 establish a duty of care that builders and their sub-contractors owe to the occupiers of property they construct and also establishes a duty of care that landlords and building owners hold towards their tenants and any third parties who might be injured by their failure to maintain or repair the property.

Following the recent concerns about the safety of buildings containing RAAC, as part of estate management duties, building owners must be able to identify if RAAC exists and ensure that measures have been out in place to properly identify, assess and mitigate any risks associated with RAAC.

Employers have a general legal responsibility to maintain the health and safety and welfare of workers, and others attending their premises (on

Employers also have a duty to consult with their employees, or their representatives, on health and safety matters. Further information is available at consulting and involving your workers (on

What guidance is available to building owners, estate owners an those responsible for managing premises?

The Health and Safety Executive (HSE) has a webpage about managing risk from RAAC (on which provides links to other guidance documents, for example from The Institute of Structural Engineers .

The Institute of Structural Engineers provides guidance on the investigation and assessment of RAAC which provides advice on the critical risk factors associated with RAAC panel construction. It includes a proposed approach to the classification of these risk factors and how these may impact on the proposed remediation and management of RAAC.

Who has the authority to close a building?

As with all health and safety risks associated with a premises, the decision to restrict access or close an area with confirmed RAAC sits with the building owner and/or estate owner and/or those responsible for managing premises.

To support building and estate owners, the Health and Safety Executive (HSE) has published guidance on managing risk from RAAC in the workplace.

What research has been undertaken on the risk RAAC poses?

Loughborough University’s experts have been studying RAAC for several years and have also undertaken a project funded by NHS England on RAAC in hospitals. The next steps in their research is at the world needs to learn how to live with RAAC from Loughborough University.

The Institution of Structural Engineers currently has a RAAC Study Group. They also published Reinforced Autoclaved Aerated Concrete (RAAC) panels: investigation and assessment (The Institution of Structural Engineers) into which the research at Loughborough contributed.

How are costs associated with RAAC managed?

As with all health and safety risks, the responsibility for any risks and costs associated with RAAC rests with the building and/or estate owners, landlords and/or those responsible for managing the premises. This includes the costs associated with identification and management of RAAC in their premises, any surveys and structural engineers to investigate the presence and condition of RAAC.

Building owners and/or estate owners, landlords and/or those responsible for managing the premises, are responsible for keeping up to date with emerging guidance from the Health and Safety Executive and The Institute of Structural Engineers.

The Welsh Government invests in the public estate through strategic capital investment programmes such as the Sustainable Learning for Communities Programme and the NHS All Wales capital programme.

The Welsh Government has provided Hywel Dda University Health Board with £12.8 million from the NHS All Wales Capital budget to manage and remediate RAAC issues identified at Withybush Hospital, in Haverfordwest.

Safety remains the top priority and it is the main responsibility of all public bodies to maintain their buildings in a safe condition.