RAAC – are the school collapses the tip of the iceberg?

by Adam Willson

13 October 2023

In recent months the issue of Reinforced Autoclaved Aerated Concrete (or “RAAC”) has dominated news headlines following a change of guidance from the Department for Education. This change was in response to RAAC in three buildings, which was previously graded as ‘non-critical’, failing and collapsing without warning over the summer.

What is RAAC?

From the 1950s to the 1990s a number of (mainly municipal) buildings were constructed using a ‘bubbly’ form of concrete known as Reinforced Autoclaved Aerated Concrete (or “RAAC”). RAAC was mainly used as precast panels in roofs (usually flat, but sometimes pitched) and occasionally in floors and walls.

The material properties and structural behaviour of RAAC differ significantly from ‘traditional’ reinforced concrete; it has proven to not be as durable and there is a risk that it can fail, particularly if it has been damaged by water or air pollution, or if it was not formed correctly when originally made.

Over the years professional advice from technical experts on RAAC has evolved, and so too has the question of how to manage its risks. However, RAAC can fail without warning, which is why there has been a change of guidance from the relevant authorities in recent weeks.

What is the extent of the problem?

A multi-disciplinary team lead by the University of Loughborough has conducted research into RAAC for a number of years and have concluded that RAAC structural panels exist in a broad cross-section of buildings. Whilst current discussions are focussed on educational buildings, these may just be the tip of the iceberg as the Loughborough research team argue that the scale of the problem is much wider, affecting many public and private buildings.

However, Professor Chris Goodier (part of the Loughborough research team and a professor of construction engineering and materials) has also stated: “It is important that the concerns around RAAC are not overstated. There is nothing from our research to indicate that RAAC fails immediately after 30 years, or that it is a dangerous material. What our research does show is that RAAC that has been poorly manufactured, installed or maintained is at greater risk of failing. The task we now face is to find out where RAAC is in buildings and assess the state it is in. Only then can we fully understand the scale of the problem and look at the best course of action to take. Ultimately, the world needs to learn how to live with RAAC”.

The overall scale of the problem is currently unknown and therefore any party involved (or potentially involved) with a property that might include RAAC in its construction (i.e. a property constructed between the 1950s and 1990s) is recommended to take action in order to understand the level of risk and mitigate the same.

Recommendation for current owners

If you own a property which might include RAAC in its construction then you are recommended to either investigate further (by reviewing operational maintenance manuals, construction drawings or other building information that might identify the type of construction) or commission a survey of the structure of the building to investigate and identify any potential RAAC. This is because as a property owner you have an on-going responsibility for repairs to the structure of the building and hold a duty of care towards your tenants and any third parties who might be injured by your failure to maintain or repair the building.

If such investigations identify RAAC present at the property then you are further recommended:

  1. to seek immediate further legal advice regarding:
    a) the extent of your responsibility to monitor, maintain, repair, replace or rectify the RAAC (particularly if the property has been let out);
    b) whether there is any right of recourse against any third parties that might assist in recouping any associated costs; and
  2. to review any insurance policy relating to the property and ascertain:
    a) whether or not it is likely to cover the cost of rectifying or mitigating any costs or losses associated with RAAC; and if so
    b) what the trigger for those costs are (i.e. does the policy only pay out in the event that the RAAC is confirmed to be defective?).

If you have had construction work carried out in the last twelve years, it is likely that the contract that you have entered into with your contractor or designers contains provisions to do with durability or the specification of certain materials. You may have recourse against your contractor or design team if you later have to carry out rectification work to eliminate the RAAC, which could cover the cost of the works. You should bear in mind that at the current time, RAAC is not deemed to be a harmful material and is not a material which is prohibited by the Construction Products Regulations, so a breach might be difficult to establish in a market-standard construction contract.

Recommendation for social housing providers

In addition to the responsibilities of a private owner (as set out above), social housing providers are subject to far more onerous regulatory and statutory obligations relating to the condition and safety of their properties. If the new social housing consumer standards are introduced, then this is only likely to become stricter and tenants will be given far more power to hold providers accountable.

The Regulator of Social Housing has contacted all registered social housing providers to set out its expectations following the discovery of RAAC in public sector buildings. That letter has stated that the regulator’s current understanding is that RAAC is not widespread in social housing, but providers are being urged to check that their buildings do not contain RAAC because it may be present in a number of buildings dating from the 1950s to 1990s.

We therefore recommend that any social housing provider takes a proactive approach by reviewing its current portfolio to determines whether the buildings are likely to contain RAAC. If so, then as well as the steps above, we would encourage you to take further legal advice to understand what further steps you should take to comply with your regulatory and statutory obligations.

Recommendation for current tenants

If you are currently tenant of a building which is suspected to contain RAAC in its construction then your lease should set out each parties’ respective responsibilities regarding the repair of the structure of the building and there may be other provisions therein which apply to the situation. You are therefore recommended to take immediate further legal advice on the provisions of the lease so that you can understand your potential exposure and what further steps you should take.

Recommendation for anyone purchasing a property that might have RAAC present

If you are either considering or in the process of purchasing a property that might have RAAC present then you are encouraged to take further legal advice on what further steps you can take to understand and mitigate any potential risks associated. This might include conducting your own survey (and instructing them to assess any potential RAAC risk), raising further enquiries about the presence of any RAAC and how it has been monitored and maintained, and ensuring that any insurance policy associated with the purchase of the property also includes cover for RAAC.

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