Deep retrofitting needed to meet UK climate targets

The UK cannot build its way to a low-carbon future without retrofitting existing homes to meet 2050 climate targets, a new report from the Institution of Engineering and Technology and Nottingham Trent University advises.

The Scaling Up Retrofit 2050 report explains that energy used in homes accounts for about 20% of UK greenhouse gas emissions and three-quarters of that comes from heating and hot water.

80% of the homes people will inhabit in 2050 have already been built, meaning it is not possible to rely on new builds alone to meet legal energy-saving targets set in the 2008 Climate Change Act.

What is deep retrofitting?

Deep retrofitting is a whole-house approach to upgrading the energy efficiency in one step as opposed to a series of incremental improvements over a long period of time. This includes adding solar panels and generating energy off grid, insulation and ventilation, and sustainable heating systems.

However, the report argues the proposition is still not attractive enough to customers. There is no effective policy driver for change, costs per home are too high as there is not yet a supply chain that can deliver deep retrofits cost effectively, in volume and at speed; and a lack of initial financing.

How can we improve energy efficiency in our homes?

The report calls for both national and local government to lead on the changes that are required, which include:

• Create clear, consistent policy objectives and a national programme for deep retrofit and climate resilience, with an initial focus on social housing
• Reduce costs and build the supply chain capacity by developing more pilot projects and demonstrators. This will bring the cost-per-property to below 30-year repair, maintenance and refurbishment budgets. This is a big economic opportunity for the supply chain
• Engage with the home owners by identifying the best ways to discuss the benefits of deep retrofit and developing trusted intermediaries to be a single point of contact for owners and tenants
• Encourage investment by creating larger projects that are more attractive to investors, by aggregating smaller retrofit projects into bigger blocks and introducing more flexible ways for local authorities to borrow and invest in retrofit programmes

IET recommends social housing take the first step in energy-efficiency retrofitting. Currently the SAP rating (Standard Assessment Protocol for evaluating the thermal efficiency of buildings) in the social housing sector has been consistently much higher than both private rental and owner-occupied.

The report argues 3,500 pilot retrofitted homes are needed in the next 2 or 3 years, with 25,000 pilots need to be completed in a 5-year period.

Rick Hartwig, IET built environment lead, said: “If we are to meet the 2050 targets of the Climate Change Act, then all housing in the UK must have zero carbon emissions from space and water heating, and space cooling.

“New and innovative products will always assist in reducing costs and improving energy performance, but sufficient work has already been done in research and pilot studies, to show that massively reducing the carbon emissions and energy requirements of current housing is achievable and needs to be done. Retrofitting has other benefits too, making cold homes warmer, healthier and reducing bills.

“A one-off deep retrofit versus 30 years of ongoing maintenance costs gives better economic outcomes and a quicker improvement in housing quality. This is not just a technological challenge; Governments – both national and local – must take the lead in encouraging and supporting the necessary changes which will in turn support clean growth.”

The full ‘Scaling Up Retrofit 2050’ report is available on the IET website.