Building ‘passports’ could prevent Raac-style safety failings – engineers

New sustainability ‘passports’ for buildings could prevent major safety failings similar to the crumbling concrete crisis, engineers have said.

Reinforced autoclaved aerated concrete (Raac) has been found in more than 100 schools, forcing them to either fully or partially close.

But University of Sheffield researchers said a new passport system could help prevent future crises and boost sustainability in Britain’s built environment.

The documentation framework, currently being developed by engineers at the university, could better record information on how buildings are designed, constructed, maintained and modified.

The researchers said it will provide key information on what materials were used, when they were last checked and when their life cycle is due to end.

They added that it also aims to help reduce waste, the demand for new raw materials and carbon emissions from the built environment by enabling more reuse and refurbishment of buildings over demolition.

Digital passports, which provide information on the supply chain, composition or carbon emissions of a product, are being developed, trialled or rolled out worldwide across a range of sectors including textiles, automotive, plastic, chemicals and electronics.

Will Mihkelson, a research associate in the university’s Department for Civil and Structural Engineering, who is leading the work, said: “Our passport system is aiming to build on the passports that currently exist for materials, so it can be used to better inform the design strategies at different stages of the lifespan of a building.

“This can help to ensure that circular economy strategies – reusing materials rather than discarding them and using new ones – can be used in construction more effectively going forward.”

Charles Gillott, a research associate in the university’s Resources, Infrastructure Systems and built Environments (RISE) Group, said: “Building passports are a very simple concept that, with little additional effort, could revolutionise the way we view built assets.

“As well as recording exactly which materials and components have been used in different areas of a building, they can help us to understand how it was constructed, should be maintained and could be adapted or deconstructed in the future.

“In the context of Raac, this would have allowed issues to be pre-empted, sped up the identification process, and enabled remediation works to be carried out much more cheaply and quickly.”

While some building passport systems already exist for specific areas of construction – such as energy, materials or health and safety – the university team said their system brings all this building data together in one place.

The key construction information is, therefore, easy to access, use, monitor and update.

The Sheffield engineers have been developing and testing their passport system on a refurbishment project led by London-based Orms architects.

Mr Mihkelson added: “We hope this will raise awareness of the need for a building passport system and create next steps towards developing an industry standard.

“We hope that building passports of the future will be stored on a central database, ideally through something like OS, so that they are accessible for decades to come and enable analyses of the UK building stock.”

Mr Mihkelson said there needs to be a consultation with industry more widely to build a consensus on the minimum required information and how to communicate this to all stakeholders.

The team are calling the industry to come together and urge Government to consider mandating passports, as they did with the Net Zero Carbon Building Standard.

Raac, which is cheaper than traditional dense concrete, was invented in Sweden in the 1930s and used in British buildings from the 1950s to the mid-1990s.

But it has a life expectancy of little more than 30 years, being less durable than concrete, and prone to collapse when moisture soaks into its aerated holes.

So far, much of the focus on Raac has been on its usage in schools, with more than 100 fully or partially closed in England due to its presence.

However, experts warn the problem could be far wider than just schools with many buildings, including hospitals, courts, offices and factories, facing issues.