The direction of travel for developments in insulation

The direction of travel for developments in insulation

In the third instalment of our feature on future building materials and solutions, Professional Builder’s Lee Jones listens to sustainable building expert Dr Matthew Brooke-Peat about the direction of travel for developments in insulation.

If we are to have any hope of achieving our carbon reduction targets then one of the key battle grounds will be in our existing housing stock, particularly in upgrading their thermal performance. Whilst recent initiatives like the Green Homes Grant may have floundered the market for suitable insulation methods is set to expand exponentially, and new approaches will be required.

In a bid to find viable solutions for builders, the government is striving to address the issue, not least with new and more stringent regulations, but also by bringing the academic and the manufacturing world together. Through his work with Leeds Beckett University’s Leeds Sustainability Institute (LSI) Dr Matthew Brooke-Peat is involved in one of those collaborations, and it is an initiative that is already promising rewards.

“We have a heritage in the LSI of researching the building performance of dwellings and have been successful in influencing changes to Building Regulations,” explains the academic institute’s Architectural Technology Course Director. “Whilst we’ve highlighted problems to industry it would be fair to say we’ve been less adept at finding solutions. There is no doubt that one of the areas that needs to be tackled in either residential retrofit or housebuilding is thermal bridging. It will be a common theme for the future, and one that we ourselves identified back in 2014.”

That insight was the inspiration for the development of the Retrofit Eaves Insulator (REI), a concept that Matthew has invented and patented with his colleague Professor Christopher Gorse, and that could represent the first in a series of innovations. With funding from a Government Knowledge Transfer Partnership (KTP) via Innovate UK – and as part of a two-year initiative with ambitions to develop similar products – his solution will now be taken towards the manufacturing stage with the help of ARC Building Solutions, a specialist in cavity fire barriers and cavity closers. Thanks to support from academic experts at LSI and the Leeds Business School, the insulation supplier is setting up its own product development division with ambitions to bring these ideas to fruition.

Matthew outlines how the REI works: “Whilst the junction between wall and roof has regularly been identified as a problem, both in new build and refurb work, the market hasn’t come up with an answer for retrofit, not least because fitting it into the eaves, filling the void appropriately, and maintaining any ventilation that might be required is difficult to deliver. The patent for the Retrofit Eaves Insulator (REI) involves a hinged semi rigid backing material, which includes the option of a ventilator tray. Beneath that sits a mineral wool insulation quilt, which provides not only the necessary thermal performance but also fire resistance. That hinging means it can be folded for transport and then recover once installed to fill the void being insulated. Multiple units could be easily transferred into a loft space by an installer, who will then simply push it into the roof space, with the material then expanding to fill the void. Insulation that’s laid at ceiling level could then be subsequently installed up to the back of the REI.”

Through modelling and prototypes, his team are confident that the concept works, and is part of a wider theme in finding other solutions a

round thermal bridging. Indeed, the idea of mechanically compressing insulation, and then releasing it to fill a confined space with restricted access, could have applications around doors and windows, for example, and form a part of more comprehensive external or internal insulation upgrade to a property.

As the recent hike in energy bills has demonstrated the imperative for new insulation products is not just in reducing carbon emissions but also in dragging significant numbers of people out of a damaging fuel poverty trap. When it comes to thermal bridging, where high rates of heat loss can often be experienced, the conundrum is how to do that in spaces which are often inherently difficult to access. “The challenge is to maintain continuity of insulation in a dwelling and the concept of recoverable insulation is certainly something that has more scope for development,” continues the lead academic on the project, “particularly since it has clear advantages in relation to thermal bridging.”

Indeed, one of the distinct advantages of the idea of recoverable insulation is that it’s a distinctly low-tech solution. All of the materials that are required to make it are already freely available and, whilst mineral wool has been used as the example here, other forms of insulation could just as easily be utilised.

“To be honest, it’s such a simple concept that, whilst I’ve been on this journey, I’ve often wondered why nobody has thought of it previously,” enthuses Matthew. “If you point a thermal imaging camera at many pitched roof buildings insulated at flat ceiling level, the problem is immediately visible, which makes its potential vast. In retrofit installations, where you’re navigating around an existing structure and fabric, thermal bridging is a real challenge, and it can be a difficult issue to overcome.”

Similarly, Matthew and his team at the LSI have previously been involved in research on the performance of thin internal wall insulation (TIWI), looking at what the optimum range and amount of material should be. “Whether it’s an internal, external or cavity wall solution, too much insulation has the potential to cause problems to the existing building fabric,” he concludes. “That’s why, particularly when it comes to retrofit, any insulation installation will need to take into account what’s already there. Given the range of building types in existence that is itself a significant task for the industry.”

For further information on the work of the Leeds Beckett University’s Leeds Sustainability Institute (LSI) visit

For further information on ARC Building Solutions, including its range of cavity fire barriers and cavity closers, visit

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