Client: Guildford Borough Council
Measures: External Wall Insulation
Date: March 2020 – October 2021
Value: Approx. £250k
Cornerstone was appointed by Guildford Borough Council to deliver a programme of external wall insulation to properties within their housing stock, as their budget allowed. Successful via an open tender process, Cornerstone was appointed in early 2020 and commenced work in the Spring.
The works involved the installation of external wall insulation and cladding to existing occupied two-storey semi-detached solid wall and timber-framed properties across the borough.
Our remit included the provision of access scaffolding, the temporary removal or replacement of rainwater goods, soil wastes and alteration to existing services. In addition, we demolished and removed existing timber mono-pitched porch front canopies and installed new GRP canopies.
A particular challenge of the scheme was developing a compliant methodology for the insulation of Swedish timber framed properties, which formed the majority of the project.
Cornerstone worked with our supplier partners to develop technically appropriate solutions for each property type. For the Swedish timber framed properties, this included stripping and strengthening the existing timber prior to the application of the EWI system.
On the Swedish timber framed properties, Cornerstone installed a mineral wool system with a silicone finish supplied by SPS Envirowall. The system was applied to a new marine-grade plywood sheathing board with a breather membrane.
On the traditional brick properties, Cornerstone installed K-Systems’ Silkolitt Pro – a premium quality silicone render with mineral wool insulation. The BBA approved product is A2 fire-rated and widely specified to simultaneously provide a thermal and aesthetic upgrade. The 110mm system has a durability in excess of 30 years.
All works were carried out in compliance with PAS 2030 by Cornerstone’s qualified installers and oversee by an experienced Site Manager.
The scheme was delivered across four locations in Guildford borough in 2020 and 2021. A total of fifteen properties were externally insulated, including three groups of Swedish timber framed properties.
This included one private rented property, where the landlord contacted us for a private quotation after seeing the transformation that had taken place on a neighbouring social property.
All insulated properties had a starting EPC rating of D and E and achieved an improvement of at least one SAP band as a result of the works.
There was also a significant improvement of the aesthetic of the properties, as well as thermal benefits enjoyed by residents. Our client Guildford Borough Council was pleased with the quality of the installations and in particular by the technical expertise we were able to contribute to insulating the hard to treat Swedish timber frame houses.