Financial Times

Diane Hubbard of Home Energy Doctor and Green Footsteps featured in the Financial Times in October 2022. She tested FT journalist Leyla Boulton’s home .

Could I make my listed London home energy-efficient and solar-powered?
LEYLA BOULTON

Efforts to equip a Georgian house with carbon-reducing tech meet outdated planning regulations.

“Don’t let Putin win” is the argument that finally convinced my son to switch off the lights
this summer. But as the Russian president cut off gas supplies to western Europe and energy
bills soared, with winter looming I decided to take things further and fight back with my
house — making it a test case of how some homeowners could face up to the energy crunch.

The obvious course of action was to install solar panels, double glazing and a heat pump — all
the “paraphernalia”, to quote Liz Truss, needed to cut both our energy consumption and CO₂
emissions. But our 200-year-old house in north London posed a particular problem. Because
it is Grade II-listed — “of special interest, warranting every effort to preserve” it — we are
barred from doing anything that might alter its appearance without planning permission.

Two years earlier, we had been discouraged from signing up to a solar panel buying scheme
offered by Islington Council on advice that the same local authority would never give us
planning permission. Double glazing too was problematic: a neighbour had been denied
retrospective approval of her new windows that looked no different from the draughty
originals.

Having discovered that the Royal Borough of Kensington and Chelsea had already eased the
rules around solar panels on its 4,000 listed houses, I wondered why Islington, which aims to
become a net zero borough by 2030, could not do the same.

My first port of call was Caroline Russell, an Islington councillor for the Green party who
arrived at the Blue Legume café on Upper Street carrying a folding bike. A past master at working
with the Labour majority on the council, she explained what levers were available for citizens
like me to pull. Following her advice, I submitted a question to the council while a friend launched a petition that would force a debate if it got 2,000 signatures.

Turning to my Georgian house’s hypothetical makeover, I asked the north London
contractors for the Solar Together scheme what they would have proposed had we joined two
years ago. For our roof, they recommended three solar panels and a battery we could charge
at a cheap overnight tariff in return for giving the grid any surplus electricity we generated
during the day.

The downside, apart from the £9,000 price tag, was that the arrangement would meet only a
fifth of our electricity needs in winter. However, it would save the equivalent of 281kg of
carbon a year — 50 per cent of the emissions from our typical usage. It would also provide
some guaranteed supply in the event of power cuts.

Moving on to our cold interior, I consulted Resi, a home renovation practice that works on
150 projects a month but usually avoids listed houses because, says chief executive Alex
Depledge, “most of the time you just end up losing money because you fight with the council
about what’s allowed”.

She arranged a visit from Diane Hubbard, an energy-efficiency specialist. Her first step was to seal up our five chimney breasts with plastic sheets and tape before pulling out a felt umbrella, or “chimney sheep”, to plug the inside of unused fireplaces.

According to Hubbard, the benefit of stopping air rising up an idle chimney can be greater than insulating floors, a loft or external walls. But such tips are not often suggested by contractors: “If I say ‘spend £20 on something like a chimney sheep’, there’s nothing a
business can sell off this.”

Hubbard then toured the house with a thermal imaging camera, as a big fan wedged in our front doorway helped to create a flow of air she could track. The resulting images revealed the
second-biggest culprit for heat loss: our front and back doors. She suggested another low-budget solution: draught-excluding door surround kits costing £22 each.

Some of the gaps that led Hubbard to give our house an E rating for energy performance — below the C minimum that will apply to new rentals from 2025 — would be costlier to fix. To stop heat flying through the roof of our extension, for example, we would have to build a false ceiling. Double glazing — of the sort that cost our neighbour £5,000 for two bedroom windows — could cut our heating demand by a third. But it was unlikely to be allowed.
That still left the toughest nut to crack — the heating itself, which like most older houses in the UK, comes from a gas-fired boiler. The environmentally sound solution would be to replace our boiler with a heat pump.

But apart from planners’ resistance to kit that would have to be installed on the outside of the
house, making heat pumps work efficiently in Georgian and Victorian terraces can be tricky.
They heat water to 40C-50C, while radiators in older UK houses are typically designed to
work with a gas boiler producing water at 70C-80C, according to Ben Allwood, an engineer
who works on decarbonising residential buildings.

Diarmaid Ward, Islington Council’s head of planning and performance, tells me that new
guidance, after two rounds of public consultation, will clarify the rules around carbon-
mitigation measures for all homes, including ones like mine. He also sends a team to look
again at my neighbour’s double glazing: she can keep her new windows after all, but a sternly
worded letter makes clear this is a one-off.

At current rates of progress in a country with some of the world’s oldest housing stock, it
would take 250 years to fit at least some renewable capacity in all UK homes which have
none.

While we wait for the officials to catch up, we’ve got our draught excluders and the chimney
sheep, but we cannot yet say we are winning.