A new in-depth home retrofit study reveals how retrofitted homes achieved energy bills up to 60% lower than a typical home

A new, in-depth, home retrofit study by the UK’s innovation agency, the Technology Strategy Board, with the support of the Energy Saving Trust, has demonstrated that retrofitted homes used as little as a quarter of the energy per square metre as a typical home of the same size.

Launched at the Retrofit Live conference at the National Centre of Refurbishment Excellence, the study report outlines the key lessons from the four-year Retrofit for the Future programme. The report is an accessible guide on how to maximise the benefits of retrofit to reduce energy consumption in existing homes.

Richard Miller, Head of Sustainability at the Technology Strategy Board commented,“This final report into our Retrofit for the Future programme categorically demonstrates that it is possible to apply effective, whole-home retrofit approaches.

“With the majority of predicted 2050 housing stock already built, and around 45% of total UK carbon emissions coming from buildings – most of that from homes, retrofitting is one of the key challenges to tackle, if the UK’s target of reducing UK carbon emissions by 80% from baseline by 2050 is to be met.”

Stephen Passmore, Technical Delivery Manager, at the Energy Saving Trust said, “Retrofit for the Future is the biggest study of its kind in the UK and has shown how industry and households can maximise the benefits of home retrofits.

“Key learnings from the study has led to priceless insight for households on how to develop successful retrofits that lead to money saved on energy bills, less carbon emissions and warmer, cosier and healthier homes.

“The message to industry is to put the occupants of homes at the heart of any retrofit, especially at the initial design and planning process to minimise costs and risks associated with any project.”

The study report is the culmination of a four-year, £17m programme, which funded the retrofit of 100 home retrofit projects across the UK. The study revealed a ‘best case’ energy use of 74% less than a typical English home per square metre and 60% lower energy bills. For a large proportion of the monitored homes, energy use was 48% lower per square metre and energy bills were 35% (£380) lower.

The Retrofit for the Future programme was initiated by the UK’s innovation agency, the Technology Strategy Board, with government support (from DCLG and the Homes and Communities Agency) and delivered with the support of industry partners including the Energy Saving Trust and the AECB.

The six point plan is:

  • Retrofit planning – Getting the project right from the very beginning with pre-design and project planning being crucial. It’s important key actions in any retrofit, such as supplier talks, local planning engagement and local resident engagement, are done as early as possible to avoid last minute changes or issues;
  • House fabric – In one home, the fabric insulation helped reduce annual space heating demand by as much as 95 per cent, illustrating the importance of good insulation. Almost all the homes significantly reduced heat loss by insulating the fabric (walls, roof, floors, windows and doors), and the most comprehensive approaches paid additional attention to insulation continuity, such as thermal bridges and air-tightness at critical junctions and openings;
  • Ensure good indoor air quality – Air-tightness keeps warmth in the home so insulation must have no gaps, and controlled ventilation is essential for fresh air movement, health, comfort and to reduce the risk of condensation and mould.
  • Choose the right services – Factors such as the design, sizing, procurement, installation, positioning and interface of services (eg heating, lighting and renewable energy) have a direct impact on the comfort and satisfaction of residents, which is why they need to be positioned and installed with care. At the same time, the ability to control the services was a common area for improvement, with control issues identified in a quarter of the properties in the study;
  • Work on site – The delivery of the retrofit on-site has a significant impact on residents and their overall satisfaction with the process, with on-site co-ordination of the project working best when a single individual or organisation takes the lead.
  • Engaging residents – Engaging residents from the start can increase their understanding and acceptance of the works and this can be a defining factor for success. The project teams took various approaches to working with people, to handing over the home and its new systems and technical support.

The study report published today builds on the interim ‘Retrofit Revealed’ report released in March 2013 and a cost analysis report released in January 2014.

The reports, detailed datasets, charts and other resources from the study are available at the dedicated, Retrofit Analysis website: www.innovateuk.org/retrofit-analysis