Reinforced Autoclaved Aerated Concrete (RAAC)

In 2023, the council asked engineering specialists to undertake inspections, focused on establishing the extent and condition of Reinforced Autoclaved Aerated Concrete (RAAC) within buildings.

RAAC is a lightweight form of precast concrete, frequently used in public sector buildings in the UK from the mid-1960s to at least the mid-1980s. It is mainly found in roofs, although occasionally in floors and walls.

In some situations, identification of concerns within some elements of RAAC has required building works to be carried out or remedial measures to be put in place.

Inspection works confirmed the presence of RAAC in the construction of some, but not all, parts of Preston Lodge High School, Prestonpans. Following a detailed option appraisal by Innovate East Lothian Ltd and FES FM Ltd (contract partners for six of the county’s secondary schools), it was agreed that a new timber structure would put in place in affected parts of the building, to support the existing roof. This option means the RAAC has become a non-structural component of the roof fabric with the roof fully supported by the new wooden structure. Work is completed.

Survey work established that RAAC was present in the dining hall at Ross High School, Tranent. Work was initially required to improve the bearing of the RAAC panels. To provide a long-term technical solution, a new timber structure was then installed in affected parts of the dining area to support the existing roof. This has resulted in the RAAC becoming a non-structural component of the roof fabric with the roof fully supported by the new wooden structure.

There is RAAC in the boiler room at Law Primary School, North Berwick. This has been assessed and is being monitored and managed appropriately. The boiler room is a restricted area and only accessed by facilities staff; there is no impact on any of the teaching, learning or office spaces. 

Survey work

Survey work confirmed that areas of the roof at the Brunton Hall in Musselburgh were constructed from RAAC. Council officers worked with structural engineering consultants to assess the condition of the RAAC within the Brunton Hall, the scale of which proved to be challenging. A report to councillors highlighted a risk that the RAAC in the Brunton Hall could deteriorate further, while there were also a number of other concerns including water ingress and the poor working environment in the building. Councillors have since approved the closure and mothballing of the Brunton Hall, with temporary alternative arrangements for service delivery to be put in place. Alternative arrangements for the Brunton Theatre Trust’s performing arts programme have been in place for some time, with performances continuing to take place at alternative venues.

The report highlighted that to permanently address RAAC issues at the Brunton Hall is unaffordable and that the preferred option is to demolish the building. However, no formal decision on demolition has been made at this time, with members agreeing that a statutory consultation will be undertaken, as the building is a common good asset.

Next steps

Councillors also agreed that a place-based development project to prepare options for future service delivery, ensuring accommodation of the arts in Musselburgh, would be undertaken. The results of this, and the consultation exercise, are to be reported back to a future Council meeting for a decision to be taken.

A small part of North Berwick Sports Centre – containing two squash rooms, trampoline room and a changing facility – is also affected and currently closed as a result. Temporary propping has been erected whilst a permanent solution is being considered as part of an option appraisal (for the permanent remedial works. The rest of the centre sports centre (including the main part of the building) remains operational and open to the public.

Some buildings at St Joseph’s School near Tranent, which has been closed since 1997, have also been identified as containing RAAC. However, most of these buildings are mothballed and so not in use. Ongoing monitoring will take place, with mitigations in place where required, until a final decision is made on the future of the buildings.