Retrofit at Scale: How Many, How Deep, At What Cost?

The current ‘top-down’ national net zero carbon policy advice from the Climate Change Committee to government sets home retrofit as a low priority. In a nutshell, it is substantially cheaper to add wind farms than to retrofit homes for delivering reduced carbon emissions. In the meantime, the vulnerability of household energy bills to shocks during an energy transition has been cruelly exposed, fuel poverty has soared, and energy retrofit funding challenges for reducing bills have increased significantly.

During preparation of the LETI Climate Emergency Retrofit Guide these issues were identified but touched on only lightly given limited resources. Consequently, a dedicated workstream was set up to address these under the strapline of ‘How many, how deep, at what cost?’. This examined how retrofit could, and should, become a mass rollout across 28 million UK homes. This RETROFIT-AT-SCALE publication is the output of this work.

The context upon which current policy advice is based needs to be changed, to show there is an alternative more equitable route to net zero carbon. This requires a fundamental rethink on how we as an industry do retrofit, including the need to significantly increase productivity to drive down costs and scale up delivery with our limited resources. It also examines wider savings if reducing housing energy demand, such as needing less energy supply infrastructure which enables redirection of funding into retrofit. Overall, it shows that a halving of home heat demand, and energy bills, can be achieved for no increase in overall cost for our route to net zero carbon.

RETROFIT-AT-SCALE is a ‘call to action’ to both policymakers and industry. It seeks to demonstrate what is possible. For LETI, it is important that this is published due to its potentially significant impact. So, with limited internal capacity, the decision was taken to enable publication under a different banner and the SDF agreed to host the report.

The RETROFIT-AT-SCALE workstream consisted of some 80 contributing volunteers made up of dedicated and passionate retrofit specialists, engineers, architects, cost consultants, contractors, suppliers, housing association professionals, academics, technicians, heritage specialists, planners, facilities managers and local authority representatives. A huge thank you must go to all the contributors who gave their free time in the common belief this commercially non-aligned document fills a large hole in the current debate about our route to net zero carbon.