Reinforced Autoclaved Aerated Concrete (RAAC): What is happening in Wales?

Published 09/11/2023   |   Reading Time minutes

On 31 August 2023, the UK Government published new guidance for RAAC in education settings following sudden failures of RAAC planks graded as ‘non-critical’ over the summer. This raised concerns about higher safety risks in buildings with RAAC.

RAAC: what it is, where it is used, why it can be a hazard

Reinforced Autoclaved Aerated Concrete (RAAC) is a form of concrete with a bubbly structure. It was used between the mid-1950s and mid-1990s for roof planks, wall panels, and floor planks. RAAC is lightweight, cost-effective, and energy efficient. It was ideal to build ready-to-assemble structures and for critical public sector buildings which needed to be built quickly.

However, due to its structure, RAAC has a shorter lifespan than traditional concrete. Over time, cracks can lead to sudden collapse. RAAC is also prone to water penetration and corrosion. Poor assembly processes (e.g. insufficient support or heavy materials on top of RAAC panels) can also lead to weaknesses.

RAAC timeline

Welsh Government
1996 Building Research Establishment (BRE) report found RAAC panels cracking and bending in homes and schools, but concluded there were no immediate safety risks .
1999 Independent body advises inspection of pre-1980 RAAC plank roofs but says there’s no risk for structural safety .
2018 Start of the work across UK to manage buildings with RAAC.
2017 UK’s Government Building Safety Programme.
2018 Department for Education and Local Government Association warns about RAAC following building failures .
Nov 2019 NHS Wales warned of RAAC Planks and investigation for RAAC in NHS buildings begins.
Feb 2020 Local authorities informed of potential RAAC issues.
May 2019 Independent body warns about 1960-1980 RAAC planks.
Jan 2022 End of investigation of RAAC in NHS buildings.
Nov 2022 Completion of the review of NHS buildings where RAAC has been identified.
14 Dec 2022 RAAC identification guidance.
16 Dec 2022 School rebuilding programme.
Feb 2023 Request by Health Boards and NHS trusts for further investigation.
March 2023 Schools requested to provide annual reports on instances or awareness of RAAC.
May 2023 Condition and energy survey of all state-funded schools and colleges commissioned by the Welsh Government.
24 Aug 2023 First attendance of the Welsh Government in the Cross-Government RAAC Working Group.
July 2023 Cross-Government RAAC Working Group established by the UK Cabinet Office.
10 Aug 2023 Health Minister visits RAAC-dependent hospitals prioritised for reconstruction.
21 Aug 2023 The UK Government invited the Welsh Government to the RAAC Working Group.
31 Aug 2023 Guidance is provided for entities and educational settings with confirmed RAAC and RAAC management details published.
UK Government
September 2023
4 Sep Written statement by the Education Minister.
8 Sep The Education and Finance Ministers release a statement about the Welsh public estate. Guidance with FAQs on RAAC is published.
12 Sep Statement by the Education Minister in Plenary.
13 Sep
Statement in the Finance Committee by the Finance Minister.
Statement in Plenary by the Health Minister.
statement by the Health Minister.
14 Sep Update of guidance on RAAC: Frequently Asked Questions.
15 Sep Written statement by the Education Minister.
22 Sep Joint written statement by the Education and Finance Ministers: All 22 local authorities have submitted updates, marking the conclusion of the initial phase of the education RAAC identification process, with the identification of four schools.
1 Sep Some evidence shared with the Welsh Government.
3 Sep Written evidence sent to the Welsh Government.
4 Sep The Education Secretary reports to Parliament on RAAC in education settings.
6 Sep Publication of education settings with RAAC identified.
7 Sep The regulator of Social Housing to has written to all registered social housing providers in England about RAAC.
12 Sep Ofsted statement about RAAC.
19 Sep
RAAC identification guidance is updated.
Guidance for responsible bodies and education settings with confirmed RAAC is updated.
RAAC management
information is updated.
A total of
174 cases of RAAC have been confirmed in educational settings in England.
5 Oct 2023 Letter from the Deputy Minister for Arts, Sport and Tourism on investigations in cultural and sporting venues.
Dec 2023 Expected completion for RAAC education buildings’ stage two inspection (detailed review)
16 Oct 2023 217 state-funded education settings identified with RAAC in England
19 Oct 2023 42 hospital sites confirmed with RAAC in England

Results of first stage inspections in Wales and next steps

Education buildings

National Education Union (NEU) Cymru called for more clarity on the issue of RAAC in schools and colleges on 1 September 2023.

The Education Minister, Jeremy Miles, told the Senedd on 12 September: “Are our schools in Wales safe? (…) Yes, they are.”

Following this, on 22 September 2023, he, and the Finance Minister, Rebecca Evans, announced that the first stage of school inspections was complete.

Four schools were identified with RAAC across Wales: Ysgol David Hughes and Ysgol Uwchradd Caergybi in Anglesey, Ysgol Maes Owen in Conwy, and Ysgol Trefnant in Denbighshire.

As of 22 September, Ysgol David Hughes had reopened; Ysgol Trefnant was about to reopen and Ysgol Uwchradd Caergybi was partially open, both with upcoming remediation work in closed affected areas. Ysgol Maes Owen was open and undergoing remediation in affected areas. The second stage of the process, i.e. detailed inspections, is expected to end in December 2023.

The first stage of inspection of further education buildings was announced as complete on 15 September. Only a small part of the Cardiff and Vale College estate had been identified as having RAAC.

RAAC was also found at Cardiff and Bangor universities. The affected areas have been closed.

As of 15 September, the second stage of detailed inspections for further education buildings was still being carried out. Universities are making their own assessments via the Association of University Estates Directors.

NHS buildings

On 13 September, the Health Minister, Eluned Morgan, reported that RAAC has been found in two hospitals, Withybush Hospital in Pembrokeshire and Nevill Hall Hospital in Monmouthshire; one decommissioned canteen building at Bryn y Neuadd Hospital in Conwy; and one non-public remote plant room at Bronglais Hospital in Ceredigion.

She said the surveying work was expected to be completed later in the autumn. She also asked her officials to commission the NHS to carry out RAAC investigations across the NHS Estates portfolio.

The NHS Estate dashboard report 2021/2022 highlights other safety concerns for Welsh hospitals beyond RAAC. The backlog of repairs associated with high or significant risk amounted to almost £650m across seven health boards and two NHS trusts for 2021/2022.

Other public buildings

St David’s Hall in Cardiff has been closed due to RAAC concerns since 7 September. The concert hall will be closed until approximately April 2025 to replace the roof.

On 5 October 2023, the Deputy Minister for Arts, Sport and Tourism, Dawn Bowden, provided a summary of RAAC investigations in cultural and sporting venues (Table 1).

Table 1: State of the RAAC investigations in cultural and sporting venues on 5 October 2023

Institution Locations inspected RAAC identified? Stage of the investigation on 5 October 2023

National Library of Wales

All X Results confirmed

Arts Council of Wales (ACW)
Theatr Clwyd X Results confirmed; ACW is planning to send a survey to all art venues in October

Sport Wales
National Centres in Sophia Gardens and Plas Menai X Results confirmed
Local museums part of the Museum Accreditation scheme


X Results confirmed
Amgueddfa Cymru


- Small risk areas Assessment of risk areas
Cadw sites


Further investigation for identified sites is almost complete

The Welsh Government has formed a cross-government group to manage the action for wider public sector buildings. Ystadau Cymru, established by the Welsh Government to encourage collaborations for the management of the public estate, has produced a survey to identify RAAC in public buildings.

The Welsh Government requested a high-level summary of the situation from local authorities and other organisations with public property portfolios by 15 September. It also asked for more detailed information for sites with RAAC “within 28 days” to determine further work.

The Welsh Government asked stock-holding local authorities to investigate the presence of RAAC in social housing and Registered Social Landlords to assess their properties via Community Housing Cymru.


The Welsh Government published RAAC guidance on 8 September, which was updated on 19 October. The guidance explains that surveying and remediation costs are the responsibility of the building or estate owners, landlords or those responsible for managing the premises.

The Finance Minister told the Senedd on 13 September 2023 that most of the remediation works for the public estate will use money already allocated for other purposes. She said it should not represent large costs in the current financial year.

The RAAC guidance mentions Welsh Government investments in public estate through programmes such as the Sustainable Learning for Communities Programme and the All Wales Capital Health Programme.

The Welsh Government has already made £12.8m available to support remediation work at Withybush Hospital.

Differences and tensions between Welsh and UK Governments

In England, as of 16 October, 217 state-funded education settings (schools, nurseries, further education colleges) had been confirmed with RAAC. 42 hospital sites had been confirmed as of 19 October. More information about the UK Government’s response for education buildings and hospitals can be found on its website.

On 4 September, the Education Minister said: “It is hugely regrettable that the evidence that has apparently been developed over the summer has been withheld until the night before the first day back of term”.

He added on 12 September that changes to UK RAAC guidance were “unexpected”. On the same day, the Rural Affairs Minister, Lesley Griffiths, said the Welsh Government was invited belatedly to RAAC meetings organised by the UK Government.

However, the UK Secretary of State for Education, Gillian Keegan, said on 4 September that her officials “have been engaging urgently with the devolved Administrations to discuss our findings and offer support (…).”. She also highlighted that education is devolved to Wales. On 6 September, she stated that the Welsh Government reacted late to the issue.

The First Minister, Mark Drakeford, told the Senedd that the impact of decisions made before devolution should be the responsibility of the UK Government. However, the Secretary of State has said funding is the responsibility of the Welsh Government since education is devolved.

Article by Amandine Debus, Elfyn Henderson & Sydney Charitos, Senedd Research, Welsh Parliament

Senedd Research acknowledges the parliamentary fellowship provided to Amandine Debus by the Natural Environment Research Council and Sydney Charitos by the Engineering and Physical Sciences Research Council, which enabled this article to be completed.