Retrofit your home to slash your energy bills

Do you want to reduce your home energy use by 75%?

That’s the remarkable energy saving achieved by Judith Leary-Joyce, one of the speakers at the energy-saving forum organised in May by HGS REACH, the RA’s climate action group. Ms Leary-Joyce owns a terraced house in a conservation area in St Albans built in 1901 and, despite her much-reduced heating bills, she says, “We’re much warmer than we ever were.” 

The event focused on the kind of significant changes that result in this kind of dramatic energy saving. Known as a ‘retrofit’, it involves insulating walls, floors, and roofs and generally taking a take-no-prisoners approach to reduce heat loss. An estate agent told Ms Leary-Joyce that the building’s exceptional eco profile would make it a ‘special sale’ and increase its value by £90,000. 

This kind of energy-saving uplift may make good financial sense. But there is another, stronger impetus. The UK’s targets for reducing climate emissions demand that all homes built before 1990 get this kind of treatment, said Dermot Barnes, associate director of sustainability at environmental consultancy XCO2, another speaker at the event. Some 30% of UK carbon emissions come from domestic buildings, with 80% coming from hot water and heating. So if the UK is to meet the targets it has set for itself, the heat loss from our homes must be dramatically reduced. 

“If we are to meet our obligations under the Climate Change Act, we would need to do 25 million comprehensive retrofits in 30 years. And that’s basically every house built before 1990,” he said. “And just to translate that massive figure into something a bit more immediate, that means 833,000 homes a year, or one every 40 seconds.” 

The homes in the Suburb almost certainly need more work than most. A REACH poll earlier this year indicated 26% are entirely single-glazed. Only 32% of residents with lofts that can be insulated said they have the recommended 270mm thickness. Some residents may think all energy-saving improvements are impossible as the HGS Trust would not permit them under the Scheme of Management. 

But Simon Henderson, HGS Trust chief executive, joined the event for the Q&A session and was keen to dispel this belief. He said the Trust is routinely approving improvements such as double glazing that matches the original design. He said: “There is a good percentage of properties on the Suburb that could have significant energy-saving improvements – but almost nobody’s applied to do them.” He also noted the Trust has no say on changes that cannot be seen from outside the building. Residents with listed homes will need Barnet’s permission for internal changes. But changes are still possible – Mr Barnes’ firm has done extensive retrofit on historic buildings such as the old Battersea Town Hall, which is Grade 2* listed. 


One of the most significant barriers to dramatic energy saving is a knowledge gap. A bad energy retrofit may not only go over budget and yield poor results but also impair ventilation, which can cause mould or other problems. Moderator Sarah Stafford, who is managing her own retrofit in the Suburb, said finding good experts is hard. Ms Leary-Joyce had to do so much research she wrote a book afterwards: Beginners Guide to Eco Renovation: Understand the Basics and the Best Questions to Ask. 

Want to know more? A full video of the event is here and there are chapter markings so you can go straight to any section that interests you (click on SHOW MORE in the YouTube description for a full list). 

 Read Dermot Barnes' presentation on energy  retrofit for older buildings here. Judith Leary-Joyce's presentation on retrofitting her home is here and you can buy her book Beginners Guide to Eco Renovation here.

Government and other assistance for improving energy efficiency changes every few months. The Energy Saving Trust has an up-to-date guide. 

Article reprinted from Suburb News, Summer 2023 edition

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Article created:15th June 2023