UK Building Safety – RAAC liability: no concrete answers

In back to school week, the presence of reinforced autoclaved aerated concrete (RAAC) in over 150 school buildings, posing a risk of collapse, dominated the headlines. However, the prevalence of RAAC in all kinds of public buildings – from court buildings to hospitals - is becoming more apparent, with schools now looking like the tip of the iceberg. The widespread use of RAAC means that it may also impact on private sector property owners, who may want to consider checking their properties for the presence of RAAC – especially large scale buildings, such as shopping centres and offices, constructed before the turn of the millennium, particularly if originally built by a local authority developer.

What is RAAC and why is it a problem?

RAAC is a lightweight building material, which was used widely in the UK from the 1950s to the 1990s, particularly (but not exclusively) in government and local authority buildings, and for flat roof structures.

Not all RAAC is problematic – if it is appropriately designed and made, and properly maintained, it can still be a useful construction material.

However, RAAC has a life span of 40 to 50 years after which it starts to crumble. This means that RAAC installed from the 1950s to the 1970s may now have reached the end of its life, and the buildings which contain it could be at risk of collapse. Given the post war building boom in the UK, a large number of buildings could potentially be affected.

In September 2022, the government sent a notice to property owners stating that “RAAC is now life-expired and liable to collapse”, and the issue is now coming to a head. Over the summer, there were instances of collapse in schools which prompted closures at the start of term and a renewed focus on the RAAC issue.

RAAC now looks set to be treated as a building defect, like asbestos or ACM cladding, which raises the question of who will be responsible for removing and replacing it, and who will foot the bill.

Extension of the Defective Premises Act

The Defective Premises Act 1972 (the DPA) imposes a duty on anyone constructing a “dwelling” (including third party contractors) to do so in a workmanlike manner using proper materials so that it is fit for habitation.

The Building Safety Act 2022 (the BSA) extended the limitation period for claims under the DPA from 6 years to 30 years for buildings completed before 28 June 2022, or 15 years for buildings completed after that date.

This means that developers of buildings constructed as long ago as 1993 could face claims under the DPA, and those who have acquired buildings completed in that period could have a route to recover the costs of RAAC removal and replacement.

While the DPA only applies to “dwellings”, the BSA also amended the DPA so that it applies to buildings “consisting of or containing” one or more dwellings. This extends it to the common parts of buildings which could be mixed use but contain at least one residential unit – for example, staff accommodation or flats above a shopping centre.

The key argument will be whether the use of RAAC was appropriate for the relevant building. Developers may argue that RAAC was, and remains, a valid building material, whereas subsequent owners will likely counter that, if the building was intended to have a life span of more than 40 – 50 years, the use and maintenance of RAAC should have been carefully considered.

Where RAAC is used for removable interior or ceiling panels, a developer could argue that, just as with other materials, it needs to be replaced periodically, which can be done without affecting the wider structure of the building. If, however, the use of RAAC is integral to the structure, such that repair will involve a wholesale demolition and rebuild, it looks more likely to fall within the DPA.

Effect on service charge

The landlord’s responsibilities for maintenance and repair of buildings, and the extent to which they can pass the costs incurred through to tenants, will vary depending on the terms of the lease.

Generally speaking, the landlord will be responsible for maintaining the structure and fabric of the building, and can pass the cost of doing so through to tenants through the service charge.

The first question is whether the mere existence of RAAC amounts to disrepair, or whether a qualitative assessment is required as to whether it has reached the safe end of its life span.  Assuming the RAAC is in disrepair, landlords can pass the cost of replacing it through to tenants under the service charge. 

However, many leases attempt to exclude tenant liability for latent defects (i.e. one that existed but was not detectable at the time of construction), or require the landlord to pursue third parties to rectify those issues.  This could protect tenants from having to pay for those repairs, and force landlords to seek recourse elsewhere.

As RAAC can be a safe construction material – albeit one requiring maintenance, and with a limited shelf life – landlords could argue that the use of RAAC in a building is not a latent defect, and may just fall within the normal maintenance and repair obligations under the lease and so fall within the service charge, helping landlords to fund those works but leaving tenants exposed.

The BSA introduced legislation preventing landlords from passing on the cost of remedial works for some fire safety defects onto certain tenants. It is not yet clear whether the government would consider introducing similar legislation to offer the same protections in terms of RAAC.

Alternatively, there is scope for the government to piggy back on existing provisions of the BSA, requiring landlords to pursue third parties before seeking to charge tenants. Those provisions are not yet in force, and the “remediation works” to which they apply are yet to be defined in secondary legislation, so could be extended to include RAAC defects.

It is likely that any government intervention would only protect residential leaseholders, and even then it is likely to depend on the scale of the problem, when that can be ascertained.

Next steps

Responsible property owners will be keen to survey their portfolio and identify any buildings containing RAAC and make sure they have an appropriate maintenance and replacement programme in place.

This is a high-level guide for the key issues to look out for; anyone who is concerned about the presence of RAAC in a building that they own or occupy should seek professional advice on their rights and liabilities as well as the available options for resolving the issue.



Authored by Lucy Redman, Mathew Ditchburn and Katie Dunn.


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