Low-carbon homes underperform, says report

The housing industry needs to make major changes if it is to meet its 2016 target for all new houses to be zero carbon, according to a new report.

The study by a team from Leeds Metropolitan University looked at the performance of a low carbon housing scheme in York, developed by the Joseph Rowntree Housing Trust who commissioned the study.

Researchers found the actual performance of the properties was not as good as intended. Heat loss was much higher than predicted - 54% more than designed for, the solar systems provided hot water but suffered numerous operational problems and the ground source heat pump system underperformed.

Elm Tree Mews was built with the aim of providing affordable, high-quality housing to meet proposed energy and carbon standards for 2013.

Malcom Bell, professor of surveying and sustainable housing at Leeds Metropolitan, who authored the report said: “Although the government has set ambitious targets for changes to building regulatory standards, which are intended to achieve zero carbon new housing by 2016, there is considerable concern that the policy will be undermined because regulatory standards will not be achieved on the ground”.

He added that many prototype designs for very low and zero carbon housing are untried and untested and do not undergo comprehensive monitoring and evaluation to check whether they have achieved their designed performance in reality.

He said: “The research project on Elm Tree Mews, where detailed monitoring was undertaken, demonstrates that the gap in performance can be large and that there is a need for fundamental change within the housebuilding industry to ensure the performance gap between aspiration and reality is closed.”

To have a better chance of meeting targets, the researchers propose a 10-year programme of change to be led by a partnership between the government and the housebuilding industry, which would include:

• a clear regulatory framework establishing a robust set of incentives and penalties to ensure standards are achieved,
• a programme of research, education and training to improve skills
• a national feedback loop to collect and analyse information on completed zero-carbon developments and chart their performance.

John Hocking, executive director of the Joseph Rowntree Housing Trust, said: “This research highlighted a number of important lessons which we have now taken forward in some of our successive housing schemes in York. Communicating and liaising with all levels of the supply chain, we have been able to apply the lessons from the Elm Tree Mews scheme so that the aspirations for our future low-carbon developments will become reality.”