Gareth Humphreys moved into a shared ownership flat in Newham, east London, in November last year.
He says he and his partner have struggled to get the interior temperature below 26 degrees Centigrade in summer, even when it is as low as 19 degrees outside. Yet the couple say they cannot raise the temperature above 17 degrees in the winter.
“During the last heatwave, from June into July, it was 30 degrees inside the flat for pretty much the entire two weeks or so. It never dropped.”
Humphreys said the property retains so much heat that temperatures inside remained above 25 degrees even when the external readings dropped to 19 degrees.
Humphreys bought the third-floor shared ownership flat with his partner, Anna, last year, paying a deposit of £15,400, along with rent of £940 a month, mortgage payments of £686, and a service charge of around £200.
“Of course like most people we don’t have air conditioning,” he says. “There is a cooling unit fitted to the property, which the developers say will keep the property at a constant temperature but it’s completely ineffective.
“We struggled to keep the temperature above 17 degrees inside the flat all through the winter. Again we were told by the developers that with the combination of the ventilation system they had and the heat network that heats the place that we shouldn’t have any issues,” says Humphreys, a 31-year-old emergency planning officer in the transport sector.
If you’re going to make half of the building glass that that’s both a heat sink in the summer and a massive bleed of heat in the winter
Despite being told that all residents would have the cooling system, only some do, and since the building’s heat pumps are not covered by the energy price cap in the same way as boilers, and it uses top up meters, “you pay a lot more than you would if you had a boiler in your property”.
Other residents have reported the same issue in the building’s group chat, Humphreys says, though not all, with some flats on different sides of the building cooler than others.
Another problem Humphreys points out is that there is no way to get through-ventilation in the flat as none of the windows or exterior doors are on opposite sides of the flat, with one side leading to the interior of the building.
There were also no curtains or blinds in the property, meaning residents have to shell out for custom ones for windows three metres high and as long as seven metres, which many residents of the block cannot afford.
“There is no consideration basically given to the fact that if you’re going to make half of the building glass that that’s both a heat sink in the summer and a massive bleed of heat in the winter.”
He and Anna, who has a disability and struggles with mobility issues and fatigue, have both been additionally fatigued due to the disrupted sleep high temperatures can cause.
He says there have also been issues with people not being able to keep certain medications in the building due to them spoiling in the heat.
“It has definitely impacted my work life as well as my personal life. There are young children living in the building, babies as well, and I know it has been affecting them.”
A Clarion Housing spokesperson said: “We recognise that recent extreme summer temperatures present challenges for many UK homes, and that balancing comfort with the move towards net-zero homes is an important issue for the housing sector to address.
“All homes at (this property) have a ventilation system, with cooling units installed in specific properties.
“We are aware of concerns raised by some residents and promptly addressed the units that were not working correctly as soon as we were made aware, with our contractors and an independent specialist confirming that the heating and ventilation systems are working as designed.
“We are continuing to engage with residents to provide guidance on how best to use these systems as part of our commitment to deliver safe, sustainable and comfortable homes.”
How can we cool London’s buildings?
The Climate Change Committee (CCC) says that around a fifth of homes in the UK are already overheating and expects that figure to increase, along with heat-related deaths, which the committee projects will exceed 10,000 in an average year by 2050.
According to the UK Health Security Agency, an estimated 358 people died at home during the 2024 heatwaves, in part due to extreme temperatures.
While the heat does not cause otherwise healthy people to die, it does exacerbate existing health conditions, such as influenza and pneumonia, circulatory diseases and dementia and Alzheimer’s.
The Met Office recently published research suggesting the chance of temperatures exceeding 30°C in the UK is now over 20 times more likely than it was in the 1960s.
The CCC found in a report earlier this year that the government’s “adaptation efforts to combat urban overheating remain weak and poorly monitored”. It also pointed to the lack of data and focus on the issue: “There are no regularly produced national datasets recording changing risks and the delivery of measures such as urban greening or building-level adaptations.”
The committee’s recommendations to the government include: improving ventilation and planning energy efficiency upgrades more efficiently; providing incentives to increase household uptake of air-to-air heat pumps which can cool as well as heat; and developing its policies on building design to specifically focus on cooling buildings.
These include improving “through” ventilation, maximising nearby green spaces, and providing shade for blocks of flats. Many countries make wider use of exterior shutters or blinds that block sunlight but not air for this purpose.
The committee is an independent statutory body which reports to Parliament on the UK’s progress to adapt to climate change every two years.
Many experts also point out that increased green space and tree cover surrounding buildings is a crucial part of keeping buildings cool.
The UK Green Building Council advocates a 3:30:300 approach: you should be able to see three trees from your home; you should have 30 per cent tree canopy cover within your neighbourhood; and you should be no more than 300 metres from a biodiverse green space or park.
In Singapore, for example, there are regulations specific to new tall buildings that enforce a green plot ratio of 1:1, or 100 per cent — that means any green space that is lost to building a new structure must be replaced on the structure, for example with rooftop gardens or urban farming. Some buildings in the country have gone so far as to create a green plot ratio of 1,100 per cent, by covering the building walls in greenery too.
Experts have also pointed out that, as it stands, the focus of the new Future Homes Standard regulations, due to be published this year, is entirely on making homes retain enough heat in the winter, and not on cooling them down in the summer.
The CCC wrote to the Government as early as 2020 to point this out, saying the lack of focus on these issues while retrofitting buildings was presenting “a high risk that poor ventilation and air-tightness will lead to overheating and poor indoor air quality”.