The Hides refurbishment gives new lease of life
A complex of low-rise flats in Harlow has been refurbished to provide residents with more energy efficient homes that also enhance the appearance of the local area.
Harlow was designated a town in March 1947 as part of the government's scheme to relieve overcrowding in London. Sir Frederick Gibberd was appointed as the architect-planner to draw up the new town masterplan that would house 60,000 people.
Now, Harlow is home to more than 85,500 people and some of the buildings in the town are around 75 years old. To bring these older buildings in to line with standards of new build properties, Harlow Council began its project to refurbish 30 flats within The Hides development which was originally built in the 1950s.
The council wanted to provide more energy efficient homes for its residents, while also refreshing the local area in a bid to tackle anti-social behaviour. The brief was to extend the life of the original building by improving its thermal performance and providing a more pleasant place for people to live.
An External Wall Insulation (EWI) system was specified to address both criteria. Building restoration specialists PJ Mear were appointed by the main contractor, Durkan, to install the EWI system. London-based architect studioap specified Saint-Gobain Weber’s webertherm XM EWI system with 110mm thick mineral fibre insulation to achieve the required U-value target.
As with any refurbishment project, working with buildings constructed decades ago using older methods and built to different standards presents its own set of challenges.
The Hides was built using Wimpey No Fines construction which posed an issue when it came to how the EWI system would be fixed to the existing structure. There were also areas with a brick skin which needed an alternative fixing. The fixing specified was a rebated fixing with a 35mm embedment into the brick, and a 65mm embedment into the No Fines concrete.
The project adopted a fabric first approach to make the flats more comfortable for residents by keeping them warmer in the winter and cooler in the summer. Other thermal improvements and design features were specified alongside the EWI system to eliminate cold bridging completely.
The new windows were brought out to be in line with the façade to remove the window recess which reduced heat leakage. A similar principle was employed both at roof level and below the damp proof course where the EWI was extended to increase thermal efficiency as well as improve air tightness.
“The combination of new doors and windows, alongside the new external wall insulation and render system will make a significant difference to the insulation, air tightness and energy efficiency of the properties,” explains Kingsley Ogalanya, site manager for Durkan. “At a time when so many people are struggling with energy bills, this sort of work is critical.”
For areas with external brick, the previous U-value was 1.84 W/m2K and was improved to 0.29 W/m2K after the installation of the EWI. The U-value for the No Fines area was originally 1.93 W/m2K but was improved to 0.29 W/m2K post-EWI installation.
From a design perspective, the council wanted to add a modern twist to the flats by using geometric colour blocks on the gable ends, and the road and courtyard facing elevations. To achieve this, Weber’s webersil TF in Winter White was chosen to give the buildings a crisp and clean aesthetic and reduce the need for maintenance due to its durability. PJ Mear used webersil TF in a range of colours - including Silver Grey, Frosted Fern and Hurricane Skies - to create the geometric design on the gable ends and front elevations.
“The plan for the flank walls to feature a multicoloured render pattern was an instant attraction to us and we knew that this was something that we would relish if given the opportunity to be involved. The Hides has been given a new lease of life and is something to really be proud of.” - Brady Burdett, estimating director at PJ Mear.
New communal lighting, fencing safety rails and a new door entry system were also installed to enhance security and make residents feel safer.
Work on the project started in August 2021 and was completed in February 2022. The project has since provided a blueprint of best practice for Harlow Council.
Winner of an INCA Award 2022, celebrating excellence in EWI, in the category for low rise refurbishment project with a traditional render finish
