This project typified many of the challenges facing Architects, builders, or self builders aiming to build a “green” private house for a sensible cost. The site was such that there no significant resources of renewable energy, such as solar or wind, so the ethos was all about pushing standards of energy efficiency hard. Another factor familiar to many residential developments was the need to bring together 100sqm of new, high quality modern, construction with retained, draughty ,badly insulated Victorian part of the home.
Targets for the energy efficiency of the new house were based on the “Silver Standard” championed by the Association of Environment Conscious Building, AECB, with insulation levels taken to the “Gold” standard.
Adopting the established low energy philosophy of ‘build tight ventilate right’ led to installation of a 24hr low level background ventilation system with Heat Recovery (MVHR). This avoided the need for trickle vents to windows and separate extract fans from bathrooms, while improving air quality and pollen levels generally.
“The project has been very successful overall, although we did discover that a builders’ views on achieving airtightness in a green-oak roof construction were dramatically different to ours. We have lost some energy efficiency I am sure through roof exfiltration, but overall the energy monitoring shows the old + new house runs on under 100kWh/sqm/yr, compared to the UK average of around 280kWh/sqm/year” – Ralph Swallow