RAAC Scandal – Campaigners Send Open Letter to Welsh Government Ministers As Welsh Residents Struggle

The UK RAAC Campaign Group has today posted an open letter to Welsh Government Ministers First Minister Eluned Morgan MS and Minister Jayne Bryant MS requesting their support for a Public Inquiry into the Use of Reinforced Autoclaved Aerated Concrete (RAAC) in Public Buildings and Housing, amid a scandal that has impacted on residents and commercial tenants across the UK.

The group is also calling for Welsh residents to support their campaign.

Here, we publish their letter in full:

Dear First Minister Eluned Morgan MS and Minister Jayne Bryant MS,

I am writing to urge the Welsh Government to publicly call for the immediate establishment of a statutory Public Inquiry into the historic approval, promotion, and widespread use of Reinforced Autoclaved Aerated Concrete (RAAC) in public housing and infrastructure across the United Kingdom. Mounting evidence indicates that the adoption of RAAC was not simply a matter of engineering misjudgment, but rather a profound failure of public oversight, transparency, and accountability that has had devastating consequences—especially for residents now discovering their homes were built with this dangerous material.

In Hirwaun, Wales, as in other parts of the UK, affected residents are now living in fear or have been forced to leave their homes. Many face financial hardship and mental anguish due to the threat of collapse, lost property value, or protracted inaction. The legacy of RAAC is not limited to construction—it is a social, economic, and moral crisis. The Welsh Government has a responsibility to protect its citizens and should play a leading role in ensuring that justice is delivered, especially if the UK Government fails to act.

The roots of this crisis are decades old, and the public deserves answers. Notably:

• Costain Group conducted research for the British Research Establishment (BRE), which directly influenced the approval of RAAC for use in system-built housing. 
• Richard Costain facilitated visits for UK politicians to Sweden to promote RAAC technology and partnered with the Edinburgh Research Unit (ERU) to develop the first Siporex towers in Scotland. 
• The ERU later created an automated building design system directing councils and the Scottish Special Housing Association (SSHA) to use specific pre-approved construction systems—such as Skarne, Jespersen, and Bison—all of which incorporated RAAC. 
• During this period, Albert Costain MP, a former Costain Group director and shareholder, promoted system-built housing in Parliament—raising serious questions about conflicts of interest and influence over public procurement. 
• Following the Ronan Point disaster, a safety review into system-built housing was mandated—but it was conducted by the BRE, an institution that had previously promoted these systems. Alarmingly, Scottish housing was excluded from that review, and Welsh housing too was left largely unscrutinised, despite widespread use of similar construction approaches across the UK.

Further deeply troubling evidence includes:

• In 1987, Edinburgh Council acknowledged RAAC-related roof risks by commissioning steel reinforcement over asbestos roofs at 159–163 Crewe Road North (Edinburgh Evening News, 22 June 1987). Later council claims that these works had no relation to RAAC have proven misleading. 
• A 1989 article in The Glasgow Observer revealed that homes in Livingston saw their value slashed by two-thirds after structural surveys condemned RAAC roofs. Although Siporex-related defects had already emerged in Basildon, Mr Gordon Davies, technical director of Livingston Development Corporation, assured the public that similar risks were unlikely in Livingston. This proved untrue, yet homes continued to be sold to unsuspecting buyers. 
• A 1967 article in the Reading Evening Post described Siporex as a remarkable new material that “floats”—even comparing it to cheese that could be “sawn” or “nailed.” In reality, RAAC is dangerously water-sensitive and disintegrates when wet. Such promotional misinformation helped normalise the use of an inherently unstable product. 
• A 2005 City of Edinburgh Council report confirmed the use of Siporex in non-traditional housing, based on a structural survey by Curtins Consulting—who now manufacture the very steel support systems being installed in Dundee to address RAAC risks. This suggests long-standing awareness and potential conflicts of interest. 
• In 2017, the Lanarkshire Valuation Joint Board classified Siporex as RAAC in official guidance, identifying its widespread use in Cumbernauld during the 1960s and 70s. This contradicts subsequent denials by North and South Lanarkshire Councils that they knew of its presence or dangers. 
• A 1989 Evening Chronicle article shows Newcastle City Council had already identified serious RAAC defects in homes with “Siporex roofs” by that time—further confirming that the risks were known and documented decades ago. 
• As early as 1959, Siporex was marketed in Scotland as a revolutionary material, claimed to be “non-combustible” and comparable to stone. Crucial information about its moisture vulnerability and long-term deterioration was conveniently omitted.

Taken together, these failures—technical, regulatory, and ethical—have left a trail of destruction: structural instability, financial devastation, and psychological trauma for countless families across the UK, including in Wales. Piecemeal responses and deflections of responsibility are no longer acceptable.

We therefore call on the Welsh Government to:

1. Publicly urge the UK Government to establish a full statutory Public Inquiry, with powers to:
   • Investigate the original approval, research, and promotion of RAAC—including the roles of BRE, Costain Group, ERU, and relevant government departments;
   • Examine the influence of corporate lobbying and potential conflicts of interest in housing policy and procurement;
   • Review the Ronan Point safety investigations and the exclusion of Scottish and Welsh properties from scrutiny;
   • Assess the human, financial, and psychological toll on affected residents and the adequacy of current remediation and compensation;
   • Recommend structural reforms to prevent such regulatory failures from recurring. 
2. Recognise the growing public demand for accountability, including:
   • Over 6,000 signatures on our UK Government petition: https://petition.parliament.uk/petitions/701337
3. Act independently if necessary to protect Welsh citizens should the UK Government fail to respond. This could include commissioning a Wales-specific investigation into RAAC’s use, establishing support structures for displaced or at-risk residents, and securing compensation pathways for affected homeowners and tenants. 

The people of Wales deserve answers and assurance that their government is prepared to defend them—especially when historic UK-wide failures are at the root of the crisis. I would welcome an opportunity to meet with you both to present the detailed evidence we have gathered and to support your engagement on this matter, whether through a UK-wide inquiry or Welsh-led action if necessary.

Thank you for your time and consideration.

Yours sincerely,

Wilson Chowdhry
Chairman, UK RAAC Campaign Group

Mr, Chowdry further explains in a statement:

“Behind every RAAC failure is a family in crisis. We’ve met residents forced to flee their homes with only hours’ notice. Parents watching children attend school in buildings at risk of collapse. Pensioners living in fear as cracks deepen in their ceilings. People who bought homes unaware that RAAC lay hidden in their walls and roofs—only to discover that repairs cost more than the property is worth.

• Share our letter and blog post on social media;
• Write to your MS (Member of the Senedd) and MP urging support
• Sign and share our UK Parliament petition: [https://petition.parliament.uk/petitions/701337]
• Sign and share our Welsh Governmnet petition: [https://petitions.senedd.wales/petitions/246606]