‘Help! A heat pump is proving no match for my brick bungalow icebox’

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Steven Oakley describes himself as a man of leisure. At 77, he has lived a storied life, spending 26 years in the Air Force, two years as a financial adviser, and a decade in Saudi Arabia. 

Now Mr Oakley lives with his wife, Eileen, 72, a former theatre nurse. The pensioners moved into their current home in December 2020 – a semi-detached bungalow in Epsom, Surrey. 

Originally built in 1954, the bungalow has been extended in several ways by previous owners: a new dining room, utility room, kitchen extension, and conservatory were added before the couple had even moved in.

The original building however does not seem to be easy to upgrade. The walls are made of solid brick and stone, making cheap cavity wall insulation a non-possibility. A previous quote for external wall insulation came in at a prohibitive £18,000, Mr Oakley said.

Nonetheless, the couple has embraced green improvements. “In our previous house, we installed a Samsung heat pump which worked as advertised,” Mr Oakley says. “Our energy bills dropped and we were very happy with it, so on moving into our current house it was a no-brainer to install a new heat pump.”

They have also installed a 6.08kWh solar panel system on the roof, which is linked to a Tesla2 storage battery, installed triple-glazing in most of the windows, bought an electric car, and installed the requisite charger.

But these improvements mean little in the face of such poor insulation. “In the winter it is cold and we have resorted to installing a log burner,” Mr Oakley said.

The Government has recently appeared to row back on the pace of some of its net zero initiatives but at the moment gas boilers are on course to be banned with heat pumps the preferred alternative.

So, is there an affordable way for Mr and Mrs Oakley to insulate their property?

Telegraph Money arranged for EPC assessor Stephen Webber to visit Mr Oakley’s home. Mr Webber, of Vibrant, said the property earned a D rating, with the potential for a C. Phil Steele, energy evangelist at Octopus Energy, also visited the bungalow.

Phil Steele, of Octopus Energy, says:

Mr Oakley’s 1950s bungalow has undergone significant renovations over the years, including an attic conversion, a rear living room extension, and a conservatory. During my visit, the infrared camera images were inconclusive due to the warm weather, but I discussed potential issues with Mr Oakley, focusing on his air source heat pump installation and possible heat loss in the home.

The air source heat pump, located in the garden, supplies hot water and heating to the house through pipework that runs into the garage where the hot water tank is located. 

During cold weather in December 2022, Mr Oakley experienced very high energy consumption, prompting a closer examination of the heat pump and possible heat loss points. 

Given the length of the pipework to the heat pump – more than 20 meters – it would be advised to run the piping underground to reduce the risk of heat loss. The insulation around the heat pump isn’t up to specification, letting in water and allowing for deterioration from the sun, so waterproof and UV insulation would help to protect the heat pump and reduce bills in the long term. 

Minor issues with the hot water tank include the positioning of the exposed copper pipe and the flexible braided pipe, which should be disconnected. Tidying up the hanging electrical wires is also advised to prevent accidental damage.

About half of the windows are triple-glazed, while the rest are double-glazed. The conservatory is also double-glazed and can be isolated from the rest of the house during cold days. There is no evidence of cavity wall insulation, and the front brick walls, especially the south-facing ones, showed higher temperatures on the infrared camera, most likely due to sunlight absorption rather than heat loss.

The irregular shape of the house, with various corners formed by extensions and rooflines intersecting, creates multiple areas for potential heat loss. There are several walls in the attic conversion that have gaps and areas missing in the insulation, while the six Velux windows pose a risk of heat loss.

The four access hatches leading to the attic have insulation boards attached, but they have small gaps around their edges, causing slight drafts. Adding curtain insulation from the inside of each hatch could help address this issue. The end wall of the attic conversion, finished with vertical hanging tiles, should be examined for proper insulation and draft barriers.

A comprehensive insulation overhaul is recommended for much of the home, especially the attic conversion. Improving the insulation around the heating pipework, checking the insulation behind the vertical tiled roof end, and addressing the heat pump’s external pipework are crucial steps to reduce heat loss and improve energy efficiency. 

Although prices can vary, I would expect an insulation installer to charge between £1,000 and £2,000 to carry out a full survey and fix the attic insulation issues and cavity wall insulation. This could achieve savings of up to £400 per year and so is a worthwhile investment.