A site on Maple Avenue, South Chingford was chosen for the government’s test-case environmental initiative, Retrofit for the Future (RftF). It was chosen because it is a typical example of many homes built in the outer suburbs of cities and towns between the 1960s-1980s. In particular,’ innovations’ common to these buildings such as flat roofs are characterised by poor quality workmanship and have relatively short life spans.
29 Maple Avenue in Chingford is a flat roofed end of terrace home of brick/block construction built in 1969. Published national statistics indicate that the greatest proportion (24%) of existing houses were constructed between 1965 – 1984 in comparison to other 20 year periods. The property is one of several within the terrace managed by forward the thinking social housing provider Ascham Homes.
The building fell way below government expectations on environmental efficiency due to the properties age, design, materials used and appliances within. While the property was unoccupied, the exercise was carried in a way that would minimise internal disruption, Retrofit for the Future projects are likely to be carried out with residents in-situ therefore the works where carried out to prove this could be done. It was a true ‘dry run’ with careful consideration given to access, providing comfortable living space, and generally minimising any internal disruption.
Southeast based building contractor, Breyer Group consulted with Ascham homes from the outset of the project and also managed the planning and funding applications through the Technology Strategy board, the government’s innovation agency and overseer of the Retrofit for the Future scheme. London based architects, ECD (Energy Conscious Design) were appointed to design a solution that would go beyond the baseline requirements of the Retrofit for the future scheme by delivering significant improvements to energy efficiency and reduction of carbon emissions. The aim was also to provide a cost effective model for Ascham Homes that can be rolled out across their stock of 12,400 properties across the Borough of Waltham in East London.
The proposed solution featured three key features:
All new kitchen appliances were chosen to the highest energy rating set out by the EU labelling scheme. Low energy and long life compact lighting units were also fitted. Heating is provided by a highly energy efficient gas combination boiler estimated to save £677 per tonne of CO2.
The concrete tile cladding was removed from the first floor and replaced with innovative vacuum insulation panels under new rain screen cladding to enhance protection and insulation. The ground floor had high performance cavity wall insulation inserted together with externally over clad brick slips for extra durability. This didn’t just improve insulation; it considerably enhanced the overall appearance.
The doors and windows were replaced Pultec high performance glass fibre units and internally, the solid ground floor was insulated using a multi-foil membrane under new timber laminate flooring.
Improvements to the building’s air tightness included the installation of an MVHR mechanical ventilation and heat recovery system. Overall, the measures have considerably reduced the demands on heating appliances and ensure heat remains inside the property for longer.
The flat roof was replaced by the Ecofin Roofgarden system. This ecologically friendly solution not only provides effective insulation and a water resistant shield that repairs itself if damaged, it also provides an organic habitat that enables plants to take root and thrive. This in itself provides yet further protection and insulation from the elements.
Solarbright, Breyer Group’s specialist solar business consulted and installed solar thermal and photo voltaic (PV) panels that fully integrate into the roof. The panels were positioned and optimised for maximum effectiveness. This provides the dual benefit of providing an additional environmentally friendly heat source - reducing demand on the gas boiler - as well as an electricity supply that can feedback surplus back into the national grid. Overall the solar heating system will save £817 per tonne of CO2 and the PV solution £412 tonne per CO2 respectively.
This project is not just a comprehensive test case of Retrofit capabilities; it’s a practical and cost effective solution that progressive housing social housing providers like Ascham Homes can take forward within their local communities.