Homeowners across the UK could be missing out on substantial savings and increased comfort because crucial energy-efficiency advice is not being offered by their builders, according to a leading eco-renovation expert.
Judith Leary-Joyce, an author and advocate for sustainable home improvements, warns that while our homes should be warm and dry, many are leaking expensive heat and driving up energy bills. She argues that a process known as 'retrofitting' – adding modern energy-saving measures to existing properties – is essential, particularly for older homes.
"Retrofit improves the energy-efficiency of your home, making it more comfortable to live in, cheaper to run and adding to its value," Leary-Joyce explains. "But builders don't yet have this on their radar. The most they're likely to do is suggest standard levels of insulation and a more efficient gas boiler."
The Overlooked Essentials of Eco-Renovation
Drawing from her own experience retrofitting a Victorian terrace, Leary-Joyce reports impressive results. Her family now saves 75% on their energy usage, lives in a considerably warmer house, and estimates their property is worth £90,000 more than an equivalent non-retrofitted home.
She details that a comprehensive retrofit should include superior insulation, enhanced airtightness to block draughts, intelligent ventilation systems to manage moisture, and sustainable heating solutions like heat pumps. However, she found that when embarking on her own project, her builder "had his own way of working and generally stuck to it. An eco builder he wasn't."
This experience prompted her to write the new book, What The Builder Won't Tell You, published by AoEC Press. In it, she identifies several key areas where builders may lack knowledge or initiative.
1. The Insulation Knowledge Gap
Leary-Joyce stresses that using the correct insulation material is critical. "There's a whole range of very effective, natural insulation materials that manage moisture well and keep you warm and cool – but the majority of builders don't know about them," she says.
She warns that builders often default to cheap, readily available synthetic, plastic-based insulation. This can trap moisture like a "big plastic bag," leading to condensation risks and making homes unbearably hot in summer. Older properties built before 1930 especially need vapour-permeable, natural materials to allow walls to breathe.
2. The Critical Role of Airtightness
Investing in fancy heating and insulation is futile if warmth escapes through countless tiny gaps. "If you insulate without airtightness, you'll be disappointed – air gets through the tiniest of gaps," Leary-Joyce cautions.
Achieving proper airtightness requires meticulous sealing of every join, plumbing inlet, and even light fittings. She admits, "I haven't yet met a standard builder who knows anything about this," advising homeowners to be vigilant and insist on this detailed work.
3. Ventilation Beyond Basic Tricks
With an airtight home, moisture produced daily by a family has nowhere to go, creating a perfect environment for mould. Leary-Joyce states that trickle vents in windows are insufficient, especially after retrofitting.
She advocates for proper mechanical ventilation systems that filter allergens, remove moisture, and can even aid in drying laundry. She suggests builders should be required to revisit properties a year later to see the consequences of poor ventilation, potentially driving stricter building regulations.
4. The Heat Pump Divide
Describing heat pumps as a 'Marmite issue' – some love them, some hate them – Leary-Joyce is clear about their efficiency when installed correctly. They provide steady warmth by drawing heat from the air or ground, even in cold weather.
Their superior efficiency is measured by the 'coefficient of performance'. For every £1 put into a gas boiler, you get about 70p of energy back. For the same £1 in an air source heat pump, you get between £3 and £4 of energy back.
Leary-Joyce concludes that builders are not deliberately withholding information, but are often simply unaware of the options. "If we homeowners understand the basics and tell the builders this is what we want, we can help drive a change," she says, towards homes that are more valuable, comfortable, and ready for a sustainable future.
What The Builder Won't Tell You by Judith Leary-Joyce is published by AoEC Press, priced £12.99, and is available now.
