Owned by Bristol City Council, Northfield House is an 18-storey block of flats, surrounded by a complex of three low-rise blocks: Berrycroft, Berchel and Mawdeley House. Rateavon were subcontracted to install external wall insulation with a brick slip finish to all four of these blocks (over 4,000m2). Alumasc’s Swisslab system was used on the ground floors and finished with traditional clay brickslips, due to its high levels of impact resistance. On the remaining floors, Swistherm with acrylic brick slips was more suitable, being a lightweight solution which minimises the structural impact of the system.
Important considerations on this project included the high wind loads effecting Northfield House and colour matching the existing brick to comply with planning.
As a result, the walls U-values were reduced to 0.29W/(m2k) from 1.75W/(m2k). Northfield tenant Marlene said: “The winter before we had the EWI cladding done it was so cold in the flat that we had to use extra heaters for hours on end, day after day. This first winter with all the work finished you could count on one hand how many times we used extra heaters. We were so much warmer and the cherry on the cake was the cheaper fuel bill.”