The use of RAAC – a complex issue

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In February 2022, the Institution of Structural Engineers published guidance which identified concerns about the possible failure of reinforced autoclaved aerated concrete (RAAC). 

This article provides a high level overview of some of the issues various parties will need to consider when RAAC is suspected of being used within a building.

What is RAAC and why did it hit the headlines?

RAAC is a lightweight material that was used mostly in flat roofing, but also in floors and walls, between the 1950s and 1990s. It is a cheaper alternative to standard concrete, is quicker to produce and easier to install, but is widely understood to be less durable. The Health and Safety Executive says that RAAC is now beyond its lifespan and may ‘collapse with little or no notice’, which will be very concerning to owners of buildings containing RAAC products, as well as those that occupy or use them. 

Many will recall that RAAC hit headline news in September 2023 when concerns were raised about RAAC products used in school buildings. The findings prevented many pupils from returning to school to start the new term. Whilst many of the affected schools have found interim solutions, there are likely to be many other at risk buildings, including private sector offices, shopping centres and warehouses. 

Identifying RAAC 

There is no central register of buildings constructed using RAAC. Identification therefore depends on local knowledge and independent inspections. 

Who pays for the costly remedial works where RAAC has been identified?

In some circumstances, the presence of RAAC might be considered a building defect, requiring expensive remedial work to address or in the worst case, demolition of the building. This raises the question of who should foot the bill if RAAC defects are identified. 

RAAC defects may be caused by various factors, either independently or in combination, assigning responsibility and cost is therefore a complex process and is seldom straightforward. Responsibility will hinge on the cause of the defect and the contractual matrix. 

The culpable parties can include architects, developers, contractors and potentially surveyors, who may have installed, specified or even missed identifying the presence of RAAC in any recent alterations to the buildings.

The landlord and tenant perspective 

If the affected premises are leasehold there are two key questions to be asked by the interested parties, where is the RAAC and what does the lease say?

The specific location of the RAAC is key. Is it inside or outside the tenant’s demise? That will have a fundamental bearing on who is responsible and what action needs to be taken. 

Once the location is known, the lease must be considered carefully to determine who bears the repairing obligations and the extent of those obligations. It is not uncommon for a landlord to be required to repair, but whether the RAAC can be repaired must be considered with the benefit of expert advice if necessary. Is the landlord able to pass the costs on to the tenant under service charges? RAAC remediation costs are likely to be significant and tenants should check their leases carefully to ensure that they are obliged to contribute if a demand is received. 

Tenants should also be wary of assuming responsibility, even if not legally but by conduct. Pro-active tenants may wish to carry out their own investigations and engage with their landlords on potential RAAC at their premises. With the benefit of professional expertise, consideration should be given to the serious consequences of RAAC failure. A considered plan of action is required on the part of both landlords and tenants when dealing with RAAC. 

Limitation issues

A hurdle for claims against the contractors and designers who installed or specified RAAC for any alleged breach of contract or professional negligence will be the statutory limitation periods for bringing claims. Where a RAAC defect has been established and potentially culpable third parties are identified, and are still in existence or maintain residual professional indemnity insurance for run-off claims post cessation of trading, the applicable limitation periods will need to be ascertained. 

The Limitation Act 1980 requires a potential claimant to bring a claim for breach of contract within six years where a contract is signed under hand, or twelve years where a contract is signed as a deed. The limitation date is often calculated by reference to practical completion, but in some cases may begin earlier or later. Given that RAAC was generally limited to use in buildings constructed between the 1950s and 1990s, contractual limitation periods are likely to have long since expired. 

The Building Safety Act 2022 (the BSA) may offer an avenue of potential redress to those with an interest in residential buildings. The BSA extended limitation periods under the Defective Premises Act 1972 (the DPA). The DPA requires that work related to the construction of a dwelling, or work on an existing dwelling, is carried out in a workmanlike or professional manner, with proper materials, and to see that the dwelling is fit for habitation. The fitness for habitation test is fairly wide-reaching. A dwelling which has been declared structurally unstable as a result of the use of RAAC will likely meet this threshold. 

Prior to 28 June 2022, the limitation period for claims under the DPA was six years from completion. However, as a result of changes introduced by the BSA, the limitation period for claims which accrued before 28 June 2022, and related to the provision of a new dwelling, was extended to 30 years. This opens up the potential opportunity for RAAC removal and replacement claims, or potentially remediation contribution order applications to be made in relation to buildings constructed up to 30 years ago. Please see our guidance to remediation contribution orders here.

For negligence claims the ordinary limitation period is six years with a further three-year period, subject to a fifteen-year long-stop, available in limited circumstances. Although the date on which the limitation period starts can be difficult to work out, given the length of time that has passed, the limitation period for bringing a claim in negligence may have long since expired.

Recent repair/retrofit works 

If there have been recent repair/retrofit works to an existing building the contractor carrying out the repair works, or the consultants involved in the design or surveying works, may have assumed responsibility for the RAAC, or for the structural integrity of the building. In this case, it might be possible to bring a claim depending upon when the repair works were carried out, regardless of whether it is a commercial or residential property. 

What are the next steps? 

If you are concerned about RAAC in a commercial or residential property, a survey by a suitably qualified professional should be undertaken to ascertain the extent of any problem and any remedial work required. 

If RAAC is present, legal advice should be obtained at an early stage to establish your rights, responsibilities and options. 

Further information

Our construction and infrastructure and property litigation teams can advise developers, building owners and leaseholders in relation to bringing and defending claims relating to the use of RAAC. 

For more information, please contact Mark Manning, Sophie Michaelides and Sian Barrett.
Please visit our Building Safety Hub for more information on the Building Safety Act 2022.

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