Why Britain’s homes and high streets need a heatwave rethink
Posted on: 26 June, 2026
By Linda Serck
Britain’s homes and high streets were designed to keep heat in, now we have to learn to keep it out. Following the June 2026 heatwave, University of the Built Environment academics Matthew Smith and Jordan Turner spoke on BBC radio about how a warming climate now demands a different approach to our residential and retail built environment.
Britain has always treated extreme hot weather as an interruption, something to be endured for a few sweaty days before the clouds return and the national conversation returns to rain.
As a result, residential and retail buildings are designed to primarily keep people warm, maximise use of daylight and optimise use of insulation. The problem now is that the same buildings designed to capture and retain heat are increasingly being asked to reject it.
In the Climate Change Committee‘s recent report, ‘A Well-Adapted UK’, independent climate advisors found that a staggering 92% of existing UK homes are likely to overheat during future heatwaves by 2050.
A report produced by Arup for the Climate Change Committee called ‘Addressing overheating risk in existing UK homes’ found that, under current weather conditions, around 55% of UK homes – that’s around 15.7 million – already fail the bedroom overheating criterion used in CIBSE’s TM59 guidance, which states that a bedroom’s operative temperature must not exceed 26°C for more than 1% of annual night-time hours (10 pm to 7 am).
Designed for cold weather
This is largely because homes in Britain have generally been designed to deal with the cold rather than overheating. With 78% of UK homes built before 1980, according to the Home Builders Federation, the difficult task is adapting millions of existing properties, often poorly prepared for hotter summers.
Matthew Smith, programme leader of our BSc Real Estate Management degree, told BBC Radio Berkshire during a ‘homes in the heatwave’ discussion: “Housing back then just was not built with the same kind of climate change imperatives that we’re building them now.”
Solar gain
Matthew said one of the most powerful forces at work is solar gain: “The sizes of windows is critical because the bigger the window, the bigger the solar gain.
“The sun’s radiation goes through glass and it’s shortwave. It warms up everything in your living rooms and your bedrooms, and that heat then is regenerated out into the space. But that’s long wave and it can’t get back through the glass. So you just get this constant greenhouse effect inside your house.”
That ‘greenhouse effect’ is one of the reasons heat can feel so stubborn indoors, particularly in bedrooms where the temperature may remain high long after sunset. It also explains why the solutions Matthew highlights are often passive cooling first before mechanical cooling comes into play, so shading windows before the sun reaches them, encouraging ventilation when outdoor air is cooler and understanding the role of thermal mass.
He said: “Because of the radiant heat from the sun, if you can shade your home and particularly your windows, then that will cut things down a lot.” He added that awnings, shutters and even closed curtains can help, although external shading is usually more effective because it stops sunlight before it hits the glass.
High streets in the heat
Jordan Turner, senior lecturer in real estate at the University of the Built Environment, sees the same contrast when looking at retail buildings and high streets. “The UK has always taken an ‘insulate heavy’ approach, maximising solar gain, mainly as a result of harsh winter conditions in which we must look to retain heat in buildings to keep warm,” he said, also speaking on BBC Radio Berkshire. Hotter countries, by contrast, often minimise solar gain through smaller windows, shutters and lighter external colours that reflect rather than absorb heat.
The comparison should not tempt Britain into simply copying Spain, Italy or Greece – the UK still needs buildings that work in February as well as August. The challenge is that buildings need to become better at seasonal intelligence, holding warmth when it is needed and resisting it when it becomes a risk. Part O of the Building Regulations, introduced in England in 2022, is one sign that this thinking has entered mainstream housing design, requiring new residential buildings to address overheating by limiting unwanted solar gain and providing ways to remove excess heat.
‘Humid stores’
Retail buildings face the same climatic double bind, but with an added commercial pressure: people have to want to spend time inside them. Large glazed frontages bring in light and attention, but they can also bring in heat. Deep retail floors can feel sealed and stale if ventilation and cooling are poor. Department stores, arcades and shopping centres may offer refuge when they are well cooled, but older high street units, particularly those inserted into historic buildings or narrow plots, may struggle to provide comfort without costly retrofit.
“The fact is that people do not want to spend time in uncomfortable, sticky, humid stores with little ventilation or cooling,” Jordan said. That matters because retail depends not only on transactions, but on dwell time. A shopper who lingers may see something unexpected, try something on, stop for coffee, wander into another shop and turn a single purchase into an afternoon. During heat spikes, Jordan said, that behaviour can change sharply: “A quick ‘in and out’ approach takes over as customers will be less likely to want to browse for other items due to the uncomfortable temperatures in stores.”
Does a heatwave reduce footfall?
The data supports that shift, although the pattern is uneven. Warm weather can boost spending on summer products. The British Retail Consortium reported that total UK retail sales rose by 3.7% year on year in May 2026 as shoppers bought clothing, footwear, household goods, electrical appliances and heatwave essentials such as fans, lighter bedding and barbecue food.
However, a Springboard report from the July 2022 heatwave showed high street footfall fell by 7.3% compared with the previous week, while city centre footfall was 11.5% lower and Central London was down 16.1%. At the same time, shopping centres and retail parks, which were more likely to offer air-conditioned environments and easier car access, saw footfall rise. The statistics show, then, that heatwaves do not necessarily reduce retail spending but changes where, how and why people shop.
Seville’s Cartuja Qanat project
This has profound implications for high street design. A successful hot-weather high street cannot rely solely on the air-conditioned interior. It needs shaded routes, trees, seating, water refill points, cooler bus stops, less heat-absorbing paving, and shopfronts designed to protect both goods and customers from glare.
In hotter cities, public space is often treated as part of the cooling system, with arcades, colonnades, awnings, courtyards and narrow streets creating a sequence of shade. Seville’s Cartuja Qanat project, for example, has explored how historic cooling principles can be adapted for modern public spaces through shade, water and airflow.
What about air conditioning?
Of course, the solution on everyone’s lips is air conditioning. Why can’t we simply add air conditioning units to homes like we do in offices? Matthew is cautious about treating air conditioning as the universal answer, partly because of energy use and emissions. Offices and shops are under pressure to rethink cooling too, he said, with approaches such as white roofs, shading and brise soleil already part of the conversation. “Climate change,” he told BBC Radio Berkshire, “is something that affects us all and we all have to be part of the answer.”
The answer to regulating temperature in our homes and high streets will involve regulation, retrofit, design and public behaviour. It will involve homes that can be shaded and ventilated, shops that are pleasant enough to browse in, and high streets that offer shelter rather than exposure. Above all, it will require Britain to stop treating heat as an occasional inconvenience and start designing for it as a regular condition of life.
