This project was an invited competition entry for the London Borough of Hounslow. The brief required proposals for low-cost, net-zero carbon family housing.
The design was developed using Passivhaus principles. An off-site manufactured building envelope features a low embodied energy, thermal bridge free timber ‘I-joist’ structure, with 350mm of blown-in cellulose fibre insulation. There is a continuous airtight layer and windows are triple-glazed throughout.
These measures provide thermal comfort and very low energy bills. They also provide acoustic comfort by significantly reducing noise pollution from outside, including aircraft, which is key given the site’s proximity to Heathrow airport.more
The glazing ratios on each facade are optimised for passive solar gain from the south in winter, while minimising heat loss from smaller windows on the north facade. The deck access and balconies to the south provide shading from the high summer sun, reducing the risk of overheating.
The homes will be fossil fuel free. All heating, cooking and hot water requirements are met via electricity and the aim is to generate the majority of this electricity on site.
Even without on-site renewables, heating bills for each home are calculated to be less than £100 per year, eradicating any potential for fuel poverty. With on-site renewables, the scheme can reach net-zero carbon.
No energy-intensive steel or concrete structure is proposed above ground. Timber, cork and stone finishes are specified internally due to their low embodied energy. External finishes include natural lime render and ‘Kenoteq Eco brick’, which is made from 90% recycled construction waste.
Ben Ridley, Amrit Marway
Bethany Waye, London Borough of Hounslow TW14