Government publishes major reports by Leeds Beckett University on energy efficiency of UK homes

We all want to live in warmer houses that are cheaper to run, and as Head of Energy Efficiency and Policy at the Leeds Sustainability Institute, I get to work on research projects to find out how we can improve the performance of our homes without it costing the earth. The Government also want us to stay healthy and warm in our homes, with the hope it results in fewer winter hospital emissions, better mental health and lower carbon emissions nationally. Over the last eight years, the LSI have undertaken three major Government research projects for the Department of Business Energy and Industrial Strategy’s (BEIS), worth almost £4 million collectively and all geared towards investigating how we can make homes more energy efficient, and crucially, if doing so can cause any unintended consequences.

In 2017, around the time of the ill-fated Green Deal, our first major report into domestic retrofits of 60 Yorkshire homes was published on the BEIS website. The report highlighted the successes and limitations of installing insulation in homes and helped inform policy and industry on the most suitable ways to approach retrofitting older homes.

Four years on, BEIS have published two more of the LSI’s major reports on energy use in homes. Coincidently, this too comes at a time when another of the Government’s green homes policy is facing criticism, the Green Homes Grant voucher scheme. Policy for more efficient and healthier homes is clearly not yet fit for purpose, not least in the context of achieving Zero Carbon and eradicating fuel poverty but also, more recently, around concerns on indoor air quality and the transmission of viruses, including COVID-19. Research makes policy better informed and we hope these latest publications will help pull future policy in more efficient and effective directions.

Both reports are based on research projects funded by the UK Government into ways to insulate homes more safely and effectively. We know that these reports are already being used by policy makers in Government to inform future decisions around domestic energy efficiency policy and building regulations, however, the reports are also accessible for industry, and for landlords and householders seeking information on what to watch out for when retrofitting their own homes.

The first report, Thin Internal Wall Insulation (TIWI), tackles the problem of how to insulate homes which do not have cavity walls. There are eight million of these homes in the UK, they are among the least efficient in the housing stock, and a higher proportion of people in fuel poverty live in these so call “solid walled” homes. Insulating these homes on the outside, for example with cladding, has several problems, not least those highlighted by the highly publicised and tragic events at Grenfell Tower. An alternative solution is to insulate the walls on the inside, called internal wall insulation (IWI). This forms the focus of TIWI, a 2-year long research project, involving several social landlords in Leeds, who allowed us to fit different types of IWI with different characteristics and thicknesses into some of their homes. We compared how each product reduced heat loss and fuel bills in the homes, while also investigating how moisture risks may manifest after the IWI was fitted. We found that reducing the thickness of the IWI leads to slightly lower fuel bill savings but has the great advantage of reducing the risk of condensation and moisture build up in the walls. These findings are already being fed into consultations for new building regulations to ensure that retrofits taking place in the future may be safer.

The second report not only brings together the cumulative knowledge acquired over the last 20 years of LSI research about the energy performance and moisture risks in homes, it also pulls in findings from the wider building performance community, to produce an opus on the energy efficiency of homes in the UK. This report was produced as part of the Demonstration of Energy Efficiency Potential (DEEP) project and identifies the common energy efficiency related problems in homes as well as their potential to be retrofitted, and where the biggest risks of doing so occurs. It looks at how building performance models do their best to predict the impact of retrofits on household bills and moisture risks, including looking at how the Energy Performance Certificate (EPC) of our homes are calculated, and outlining where improvements to models could be made. This document is the first of its kind to bring together such comprehensive knowledge and findings from the research community on the energy efficiency of homes and condenses it into a single accessible report. The review stands alone as a 'go to' place to get information on the energy efficiency of homes, but also sets the context for the rest of the DEEP project.

Over the next few years more findings and publications from the DEEP project are expected to answer questions such as: How much can fuel bills be reduced through different retrofit approaches? Should homes be retrofitted step-by-step or all in one go? Are government models of energy and moisture in homes accurate and how can these be improved? DEEP will be a three year, £3 million research project.

For more information relating to these publications please contact Dr David Glew, Head of Energy Efficiency and Policy in the LSI, and lead for both these projects.