RAAC in the UK: Concerns and government response

What is RAAC?

Reinforced aerated autoclaved concrete (RAAC) is a type of lightweight concrete which, unlike traditional concrete, does not contain gravel and pieces of crushed stone. It was used in the UK between the 1950s and 1990s, mostly to construct public buildings, such as schools and hospitals.

RAAC came to public and media attention in 2023, when the Department for Education (DfE) advised schools to close buildings with RAAC until safety work took place, just before the start of term.

Concerns about RAAC

Concerns about RAAC use in the UK were first raised in 1996 by the Building Research Establishment, which found “cracking” and “corrosion” in RAAC roofing panels. In 2019, the Standing Committee on Structural Safety, an industry body, warned that RAAC planks were “past their expected service life” and that roofs with RAAC planks could collapse (PDF).

The Royal Institution of Chartered Surveyors states that RAAC in roofing panels could pose a structural risk, particularly if the RAAC was installed incorrectly or if there are leaks. The porous structure of RAAC allows water to enter, which can cause its internal steel reinforcements to corrode and lead to cracking.

Identification and mitigation of RAAC

There is no comprehensive list of which buildings contain RAAC. To identify whether RAAC was used in a building, surveys need to be carried out.

The Institute of Structural Engineers advises building owners to determine whether their buildings contain RAAC. A building’s condition will determine whether monitoring its RAAC panels is appropriate or whether “remedial propping or strengthening works” need to be carried out. In some cases, RAAC panels may need to be replaced.

RAAC in public buildings

The government says individual departments and arms-length bodies are responsible for identifying and managing RAAC in their estates. It also said it would consider funding for public buildings “on a case-by-case basis”.

RAAC has also been identified in buildings in the devolved administrations. The devolved administrations are responsible for managing issues with RAAC in their areas and any related funding.

RAAC in schools

In December 2018, the DfE advised bodies responsible for schools, such as local authorities, to identify “any RAAC property in their portfolio”. The DfE has also been collecting information on RAAC in schools.

In the summer of 2023 RAAC panels in three buildings, which the DfE said would have been judged as “non-critical” on a visual inspection, collapsed. The DfE then advised schools to close all spaces with RAAC, just before the start of term (PDF). Twenty of the 235 schools with suspected RAAC moved to a mix of in-person and online teaching, 19 delayed the start of term and four moved to fully remote learning.

As of 27 November 2023, RAAC has been confirmed in 231 state-funded education settings. Face-to-face teaching was offered in 227 of them.

The DfE said it would provide funding for one-off mitigation works in schools and approve “reasonable requests” for help with operational costs. The DfE said it would also fund “longer-term refurbishment or rebuilding projects”, for example through the School Rebuilding Programme.

RAAC in hospitals

NHS England asked all NHS trusts to identify RAAC on their estates in May 2019 and again in September 2023. As of 17 October 2023, NHS trusts have identified RAAC in 45 hospitals sites.

The Department of Health and Social Care (DHSC) has set up a remediation programme to monitor and mitigate RAAC across the NHS estate. It has committed to removing RAAC from the estate by 2035 and pledged £698 million from 2021 to 2025 to remediate RAAC.

The DHSC said that “in most identified cases, RAAC has been found in limited parts of a building”. It has already been removed from three sites. Seven hospitals with RAAC will be rebuilt as part of the New Hospitals Programme.

RAAC in privately owned buildings

The government has said individual building owners and managers are responsible for “responding to safety alerts such as RAAC”.

Building owners and managers have responsibilities under different pieces of legislation, including the Defective Premises Act 1972 and Occupiers’ Liability Act 1957, for the maintenance of their buildings’ structure and the safety of employees, tenants and members of the public.