So delighted are the housebuilders with the trial that they have placed an order to build a further 30 homes in timber frame, and Sunley is looking at using the system at another of its sites.
"The first houses took 24 to 26 weeks to build, because at West Malling we have a fairly complex product," says Andy Wibling, managing director with Sunley Homes. The trial four-bedroom house was built in just 17 days, although Wibling admits "that was double-ganged and double-supervised". The next homes should each take about nine weeks to build, he estimates.
Rather than sourcing timber frame from a UK supplier, Sunley became the first UK housebuilder to sign up to the Super E House programme, which aims to introduce Canadian makers of timber-frame systems and technology such as heat-recovery ventilation systems to UK housebuilders.
The programme was developed by National Resources Canada, a department of the Canadian government, and first promoted in Japan. It is based on Canada's R-2000 programme, which promotes energy-efficient, environmentally responsible homes that offer health benefits such as improved air quality through mechanical ventilation and heat-recovery technology. In signing up to Super E House, a UK housebuilder effectively enters a partnering relationship with a Canadian house production company – in Sunley's case Quebec-based timber-frame maker, MIC-Alouette – and signs a licence agreement with the Canadian government. As timber frame is shipped from Canada, Sunley has to place its order 16 weeks in advance of delivery, so it expects its next houses to be erected in September.
The next homes will be similar to the prototype. "We're looking at significantly reducing the heating," says Wibling. "We're doing calculations of running costs, but we estimate there will be a 40% reduction in heating costs."
Wibling says Sunley's first Canadian house, currently a show house, cost about 6-8% more to build than a traditional home. "But we have gained in added value – in energy-efficiency, quality, sound reduction and health. We hope that design development will bring future costs down, or that we will be able to provide added value, such as air-conditioning, in homes at no extra cost to us."
Developer Sunley Homes and Environ Country Homes Architect Clague Timber frame MIC-Alouette