Government 'to fail' on homes carbon target
The housing industry needs to rethink the whole construction process if the Government is to meet its target for all new homes to be zero-carbon by 2016, a report has claimed.
According to the National Trust, a study of a housing development on Trust land near Altrincham, Cheshire, showed large-scale building could deliver high environmental standards on water and energy consumption.
But the project also revealed there were currently a number of obstacles, ranging from gaps between predicted energy conservation in the design and actual performance to a lack of labour and environmentally sustainable products in the UK.
The National Trust said a strong sense of direction from the Government and wholehearted support from the construction industry was "vital" if the 2016 zero-carbon targets were to be met.
Some 700 homes are being built in the Stamford Brook development on land formerly part of the Dunham Massey estate in a scheme which aims to fund the upkeep of the stately home and land, but which has attracted controversy.
The site, on which around 250 homes have been completed, does not include microgeneration renewables such as wind turbines or solar panels and therefore cannot be zero-carbon.
But the homes are built to high energy standards using sustainable materials, while the development has been laid out with a high proportion of green spaces, footpaths, cycle routes and wildlife corridors, the National Trust said.
In order to plan for flooding risk, climate change projections over 100 years were used and Sinderland Brook, which runs through the area, has been restored to a meandering stream with its natural floodplain.
According to the report by the Trust and construction firms Bryant Homes and Redrow Homes, one of the major challenges for sustainable buildings was the lack of suitable products.
For instance, wooden-framed double-glazed windows had to be sourced from Scandinavia for the first phase of building because of a lack of availability in the UK. And prohibitive costs have led to the abandoning of the product in favour of the less-environmentally friendly uPVC windows for the following stages.
According to Government-funded research undertaken as part of the project, the development showed traditional building methods such as cavity wall construction and use of masonry could be as energy efficient as other techniques.
But while the houses meet level three of the new Code for Sustainable Homes, they would need a "step-change" in design to meet level four without low-carbon energy generation. Zero-carbon homes will be level six in the code.
Researchers from Leeds Metropolitan University warned: "The volume house-building industry will struggle to meet enhanced energy performance standards for reasons that are deeply embedded in the culture, processes and practice at all levels in the industry." Greater Government regulation and more robust enforcement are required to deliver energy savings, the Trust and construction firms said.
Rob Jarman, head of sustainability and environmental practices at the National Trust, said: "Stamford Brook is proof that a housing development can work when it combines the reality of commercial needs and a vision of better building in terms of environmental standards.
"A strong sense of direction from Government and wholehearted support from the construction industry is vital if we're to achieve the target that all new homes should be zero-carbon by 2016."
The researchers from Leeds Metropolitan University said there can be "significant and quantifiable discrepancies" between designed energy performance and levels achieved in use or testing, in part because of construction defects.
Image: A finished section of the Stamford Brook development, built on part of the National Trust's Dunham Massey estate [National Trust]