Knauf Insulation has shown that its Supafil Party Wall glass mineral wool blowing insulation is a reliable way of eliminating party wall bypass and so City West Housing Trust in Salford has installed the product as part of a pilot scheme to a number of its properties.

When completed, the trials will measure the extent of customers’ energy bill savings – estimated to be up to £90 a year – as well as the amount of carbon emissions that could be reduced.

Research undertaken by Leeds Metropolitan University, MIMA (the Mineral Wool Manufacturers’ Trade Association), BRE (Building Research Establishment) and Knauf Insulation has revealed that a significant amount of heat is lost through uninsulated cavity party walls.

Garry Vaughan, Head of Supply Chain and Sustainability at City West, said: “After discovering the research of party wall bypass, we knew that by insulating the cavity party walls of properties we could achieve lower energy bills for our customers and so we embarked on a trial project – with the aim of a possible roll out across other areas in the North West.”

Matthew Prowse, Application Development Manager for Knauf Insulation commented: “Supafil Party Wall prevents heat loss through party separating cavity walls and when used in conjunction with effective edge sealing the solution allows a zero effective U-value to be used within SAP calculations for new dwellings.

“Supafil Party Wall insulation also has good sound absorption characteristics which helps to ensure that when a party wall is upgraded, it complies with the requirements of Approved Document Part E of the Building Regulations"

Garry Vaughan continued: “We tested the houses before and after the installation took place. The reduction in the heat loss was equivalent to an improvement in the effective U-value of the party wall of at least 0.5 W/m2K."