By Dentons’ Philip Knight, Fiona MacGregor and Scott Buchanan
REINFORCED autoclaved aerated concrete (RAAC) is a lightweight concrete that was widely used in the construction of commercial and public buildings, typically in ceilings, floors or walls, between the 1950s and 1990s. It was adopted as an alternative to ‘traditional’ concrete as it was cheaper to purchase, quicker to produce and easier to install.
In 2023, RAAC became a hot topic due to several high-profile instances of sudden failure of RAAC panels. This has led commercial landlords and tenants alike to worry about whether any of the properties in their portfolio contain RAAC, and how to deal with RAAC if it is found.
Scottish Government data suggests that as of November 2024, 16 landlords had reported 2,445 RAAC-affected properties in the rented housing sector alone, most of which were social housing.
While there are no official figures for the number of RAAC-affected public buildings in Scotland, a National Services Scotland response to a Freedom of Information request in November 2023 referred to an NHS Scotland estimate that 254 of its buildings were suspected of containing RAAC. Scottish Government research also showed that as of September 2023, half of Scotland’s local authorities had identified RAAC in schools.
Unsurprisingly in view of the alarming media coverage of the RAAC issue, the knee-jerk response of landlords and tenants who discover their properties contain RAAC is to urgently instruct construction firms to carry out immediate repairs. While discovering RAAC is present in a building is a serious matter that warrants thorough investigation, identifying the presence of RAAC does not always necessitate immediate repairs.
RAAC is commonly perceived as having a life expectancy of 30 years, however the Institute of Structural Engineers considers the lifespan of RAAC ultimately depends on several factors, including if the RAAC was manufactured and installed correctly and has been appropriately maintained since installation.
Maintenance queries include checking that the RAAC panels have not been overloaded, there has been no water ingress that has caused damage to the RAAC panels, and the RAAC panels are adequately supported. If the RAAC panels satisfy these criteria, then its durability is comparable to that of similar materials – such as traditional concrete.
Therefore, the mere presence of RAAC does not mean the property is defective and at risk of sudden failure.
Who is responsible?
Responsibility for repairing and maintaining RAAC in commercial buildings will depend on the terms of the commercial lease. A typical commercial lease will require a tenant to ensure the premises are kept in ‘good and substantial repair’. If the RAAC is not in disrepair and is being maintained, tenants will not be obliged under most commercial leases to take any additional action.
If the RAAC is damaged or failing, however, then it will usually be the tenant who is required to repair the premises and restore its condition to meet the standard of good and substantial repair.
In some cases, the reason for the RAAC failure and/or the works required to remedy the issue may be so significant and expensive as to give rise to an ‘extraordinary’ repair requirement. An extraordinary repair is a Scots law concept used for the most serious repairs, as opposed to ‘run of the mill’ repairs.
Under common law, a commercial landlord is responsible for extraordinary repairs; however, the majority of commercial leases transfer responsibility and liability for extraordinary repairs to the tenant by making the tenant responsible for all repairs, irrespective of their cause and the age or state of dilapidation.
Before considering who may be liable to repair any RAAC, it is important to understand the cause, extent and cost of the repair and to check the terms of the lease to understand who is liable for extraordinary repairs.
If the premises form part of a wider building and RAAC is located in the common parts as opposed to the let premises, liability for carrying out any repairs, and recovery of the costs of repairs will depend on the terms of the lease and a bespoke review will be required.
Whatever the circumstances, it is important that landlords and tenants react appropriately, according to the terms of the lease and relevant regulations.
Beyond the breach of the lease obligations, a failure to act could lead to a breach of statutory obligations in respect of occupiers liability or health and safety, leading to far more serious consequences and higher costs than would likely be incurred from taking steps to get the RAAC repaired.
• Philip Knight is a partner in the disputes practice in Dentons’ Edinburgh office; Fiona MacGregor is a counsel and Scott Buchanan is an associate in the disputes practice in Dentons’ Glasgow office.
