Retrofitting should have a targeted role in the decarbonisation of UK heat – ETI report
15 November 2016
A new and targeted approach is needed to retrofit selective parts of the UK’s housing stock to allow it to contribute to a cost effective decarbonisation strategy, according to a report published today by the ETI.
“Housing Retrofits – A New Start” written by the ETI’s Chief Engineer Andrew Haslett looks at the role of housing retrofitting when seeking to tackle the 20% of emissions that comes from heating the UK’s 28 million homes.
The ETI report follows the completion of a second project in the area of housing retrofits. The first project identified two new retrofitting approaches with significant potential to reduce wasted time and materials, reduce costs and improve quality through industrialising the planning and execution of housing retrofits.
The second project set out to test this more industrialised approach on five typical UK dwellings (terrace, semi-detached, detached) built from pre-1919 to post 1980, to identify what might be deliverable in practise. Retrofits were successfully completed on four of the houses, with gas usage reduced by 30-50% at costs ranging from £32,000 to £77,000. The results from the project team show how supply chain investment and learning might reduce the cost range to £17,000 to £31,000.
The report says that although deeper retrofits of houses are technically feasible, their cost could be potentially similar to rebuilding the entire UK housing stock, so a more targeted approach is needed.
Selective housing retrofits can still contribute to cost-effective health, housing and decarbonisation strategies but there will need to be significant investment in the supply chain to help improve delivery.
The report highlights research that shows that most consumers are not motivated to spend money on efficiency measures so a combination of improved comfort and amenity, improved supply chain performance and mechanisms that mandate or reward carbon savings will be required, both in the social and private sectors.
The report identifies that the current major opportunity to improve housing efficiency at modest carbon prices lies in tackling the c4million hard to treat cavity walls across the UK. It also says that retrofitting programmes should not work in isolation but in partnership with the development of local area energy plans and advanced home heating controls to bring an overall system approach to the decarbonisation of heat in the UK.
Andrew Haslett Chief Engineer Improving the thermal efficiency of significant parts of the existing UK housing stock over the next 30 years is an important part of a cost-effective UK decarbonisation strategy but it cannot substitute for decarbonising the supply of energy to buildings.
Although very deep housing retrofits are technically feasible, their cost could potentially be similar to the greater than two trillion pound cost of rebuilding the entire UK housing stock, so a more targeted approach is needed.
There are significant opportunities to improve the performance of a traditional business-as-usual approach to housing retrofits. A coherent long-term strategy that recognises the underlying economics will enable more entrepreneurial businesses to invest in the changes required to deliver more cost-effective, high performing retrofits more aligned to the needs and drivers of home owners.