U-values have been upgraded in Bristol council homes using an external wall insulation (EWI) system from Knauf Marmorit’s Warm Wall range, which cuts energy costs by reducing heat loss through the external façade. The works are part of a phased repair and improvement programme by Bristol City Council to upgrade its stock of 1920s PRC (precast reinforced concrete) houses in the Sea Mills conservation area.

In excess of 20,000m2 of Knauf Mamorit’s Warm Wall EWI has been installed to approximately half of the 247 houses in the scheme to date. This has helped to achieve a U-value of 0.28W/m2K on the properties, and with no need for tenants to move out while the Warm Wall was installed.

The system was specified with 50mm insulation board and a two-coat render. The render basecoat is Marmorit’s SM700, with a top coat of Marmorit’s 1.5mm SP260 mineral based textured render system, which provides a hardwearing external finish. The whole scheme is due to be completed in the spring of 2014.