Major changes in the house-building industry needed if zero carbon targets are to be met

Low Carbon Housing: Lessons from Elm Tree Mews, by a team from Leeds Metropolitan University, looked at the features and performance of a low carbon housing scheme in York, developed by the Joseph Rowntree Housing Trust.

Elm Tree Mews was built with the aim of providing affordable, high-quality housing to meet proposed energy and carbon standards for 2013. The research project, commissioned by the Joseph Rowntree Foundation, aimed to evaluate the overall energy and carbon performance of the scheme, the impact design has on performance and the influence that interactions between residents and their homes can have on performance.

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.

Lead author, Malcom Bell, Professor of Surveying and Sustainable Housing at Leeds Metropolitan, 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.

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. 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 house-building industry to ensure the performance gap between aspiration and reality is closed."

A number of issues – including better monitoring, more rigorous evaluation, and better support and training for the industry – need to be taken into consideration. Many processes and cultures within the industry and its supply chain need to change if zero carbon housing is to become a reality:

• Procurement – Housing providers need to take more interest in the energy and carbon performance of homes, ensuring that claims made by designers, contractors, developers and suppliers are supported by robust evidence.
• Design – Design processes should be improved to focus on the likely performance in practice rather than theoretical estimates, and more consideration needs to be given to support low carbon lifestyles.
• Construction –Processes need to be improved to include in-production testing and ensure changes during construction are closely controlled so that housing energy performance is not compromised.
• Resident support – Developers and landlords should provide meaningful guidance and support for residents on using their homes to support energy efficiency

To have a better chance of meeting targets, the researchers proposed a ten-year programme of change to be led by a partnership between the government and the house-building 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 – consisting of pilot studies, research and development and training to improve skills throughout the industry.
• 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."

However, this research highlighted a number of wider issues which need to be addressed by government and the house building industry if the desired zero-carbon standards are to be met including the need for more systemic support to ensure all those involved work together to achieve this goal."