Sheep Wool External Wall Insulation

PROBLEM

The Clean Growth Strategy unequivocally identified decarbonising heat as the UK's greatest challenge in meeting carbon targets, emphasising the urgent need for action and innovation. Efficient new builds will have limited impact due to slow stock replacement rates, thus the challenge lies in retrofitting the existing inefficient stock.

Solid wall housing makes up a large part of the UK's ageing housing stock, and is among the worst performing thermal envelopes. External wall insulation (EWI) is the preferred method for improving the thermal efficiency of these households. By 2025 we need to be installing EWI measures to 250,000 homes yearly to meet net-zero targets, 22x the number delivered in 2019\.

This will require a significant investment in building components. Traditional EWI panels are derived from energy intensive manufacturing processes (eg mineral wool) or oil-based feedstocks (eg EPS). This presents an opportunity to design for resource efficiency, by developing a low embodied carbon alternative using sustainable raw materials local to the UK.

INNOVATION

This project will fund industrial research to develop a chemical process for scalably producing rigid EWI panels from sheep wool. This fibre has excellent insulative properties which have led to its use in low-density soft rolled insulation, however no high-density rigid panelling product currently exists.

The innovation focus is the development of an effective binder formulation and low-energy processing route that will crosslink and adhere the wool fibres together into a stiff structure. We will leverage advanced materials and novel green chemistries to meet performance, sustainability, and cost-efficiency targets.

Once optimised at the lab-scale, the process will be scaled-up to manufacture panels to production size. These will be tested to evaluate industry standard properties including fire-resistance, thermal conductivity, and mechanical durability.

IMPACT

This innovation leverages an under-utilised natural fibre by-product, enabling its reuse and addressing its current status as a net loss product for British farmers.

By promoting a circular economy, it maximises return on investment and reduces the immediate carbon cost associated with retrofitting the UK's ageing housing stock. Achieving circularity in building materials enhances supply chain resilience and directly benefits economically deprived rural communities. The use of natural binders and green chemistry, mean the panels produced could eventually biodegrade, minimising waste.

This project assembles a consortium of partners and subcontractors across Wales, Scotland, and the North of England. This work is only possible through specialist collaboration from experts in the wool, building, and advanced materials sectors.