Hotter Summers Might Change Your New Home Buying Checklist

Britain’s latest heatwave of summer 2026 has left plenty of households with sleepless nights, overheated bedrooms and homes that take hours to cool down. As extreme heat becomes something buyers need to plan for rather than shrug off, it’s worth thinking differently about what actually makesa property comfortable, efficient and affordable to run. 

British homes have traditionally been designed around one problem, keeping warm. Buyers look for double glazing, insulation, efficient heating and a strong Energy Performance Certificate rating, and all of that still matters, especially when winter energy bills already put pressure on household budgets. 

But the latest heatwave has exposed the other side of the coin. A home that holds onto heat brilliantly in winter can just as easily become unbearable in summer if it has large unshaded windows, poor ventilation, or bedrooms sitting directly under the roof.1 

For anyone house hunting right now, summer comfort is becoming much harder to ignore. A bright, sun-filled room might look gorgeous at a viewing, but it could be a nightmare to sleep, work or relax in once the temperature climbs. 

The questions to ask at a viewing 

A single viewing rarely tells you how a home copes with a proper hot spell. A room might feel perfectly pleasant in spring or autumn and turn stifling in July. A top-floor bedroom can hold onto heat long after sunset, while a glass extension might be unusable for weeks of the summer. 

Before you make an offer, ask the seller: 

• Does the property get uncomfortably hot in warm weather? 

• Which rooms are worst affected? 

• Does it cool down properly overnight? 

• Are fans or air-conditioning units used regularly? 

• Can windows be opened safely once it’s cooler? 

• Is there decent shading on the sunniest windows? 

• Have the current owners made any changes to tackle overheating? 

The answers won’t replace a proper independent assessment, but they can flag a problem that’s easy to miss in a twenty minute walkaround. 

Five warning signs your next home might struggle in the heat 

1. Large windows with little shade

Big windows flood a home with natural light, but they also let in a lot of solar heat. East-facing rooms can warm quickly in the morning, while south and west-facing rooms can bake for hours later in the day. Conservatories, roof lights, glass extensions and floor-to-ceiling windows are particularly exposed. 

Look for external shutters, awnings, roof overhangs, decent blinds, nearby trees, or solar-control glazing. Double and triple glazing help keep winter heat in, but they won’t stop a room overheating in summer on their own. 

2. Bedrooms directly under the roof

Top-floor flats and loft conversions can become the hottest rooms in the building. The roof soaks up heat all day, which can leave bedrooms uncomfortably warm long after the temperature outside has dropped, and that can seriously disrupt sleep. 

Ask whether fans or portable air-conditioning units get used regularly, and whether the windows can be opened safely overnight. Cooling equipment being present isn’t automatically a red flag, but it can be a sign the room is hard to keep comfortable without extra electricity use. 

3. Windows on only one side of the property

Homes are generally easier to cool when air can actually move through them. Windows on opposite sides create cross-ventilation once it’s cooler outside than in. That’s harder to achieve in flats with windows on only one side, in rooms with no natural ventilation, or on busy roads where noise and pollution make leaving windows open impractical. 

Check which windows open, how far, whether there are trickle vents, whether extractor fans actually work, whether air can move between rooms, and whether any mechanical ventilation has been properly maintained. Opening windows during the hottest part of the day can actually let more warm air in. Ventilation tends to work better later in the day or overnight. 

4. A heavily glazed extension

Glass extensions and conservatories can look stunning at a viewing, but without the right glazing, shading, ventilation and insulation, they can be roasting in summer and freezing in winter. 

Think honestly about whether the space could realistically be used all year round. Ask whether blinds, roof vents, fans or cooling equipment are needed in summer, and what it costs to heat the room in winter. A room that’s uncomfortable for several months a year offers you a lot less usable space than the floor plan suggests. 

5. No practical way to add cooling or shading

Some homes are easy to adapt. Others aren’t. Leaseholders may need permission from the freeholder or managing agent before fitting external shutters, awnings, air-conditioning or a heat pump, and planning, noise or building requirements may apply depending on the property and location. 

Before buying somewhere that looks prone to overheating, check whether improvements would actually be allowed, practical and affordable. 

Is insulation the problem? 

Not on its own. Properly installed insulation slows the movement of heat through a building, which helps you stay warm in winter and can delay heat getting in during summer. 

The real issue is when heat gets in and can’t get back out. A well-insulated, airtight home still needs proper shading, glazing and ventilation. Without them, heat from sunlight, cooking, appliances and just having people in the house builds up indoors. The goal isn’t a home that holds heat, it’s one that manages heat properly all year round. 

Could air conditioning become more common? 

Air conditioning has always been seen as a bit of a luxury in British homes, but repeated heatwaves might well change that, especially for top-floor flats, loft conversions, home offices and heavily glazed properties. 

Portable units can cool individual rooms, but they can be noisy, take up floor space and need a hose to vent hot air outside. Fixed systems tend to work better, though installation can be costly and usually needs an external unit. Air conditioning also pushes up electricity use, so weigh up the running cost alongside the purchase price. 

It’s often more sensible to cut down the heat getting in first, through shading, better glazing and improved ventilation, and only look at mechanical cooling if that’s not enough. 

Can a heat pump cool a home? 

Depends on the type. Most air-to-water heat pumps installed in UK homes provide heating and hot water, and shouldn’t be assumed to cool rooms too.2 

Air-to-air heat pumps distribute heated or cooled air through indoor units and can provide both warmth in winter and cooling in summer, though they don’t normally produce hot water, so you’d need a separate system for that. 

If you’re looking at a property with a heat pump, ask what type it is, whether it provides cooling, when it was last serviced, whether any warranties are still in place, and what the running costs have actually been. 

Don’t rely on the EPC alone 

An Energy Performance Certificate gives you useful information about a property’s estimated energy efficiency and possible improvements, but it won’t tell you everything about how the home feels in a heatwave.3 

It won’t reveal that a west-facing bedroom turns into an oven by evening, that traffic noise means the windows can never be open, or that a glass extension is unbearable in summer. Treat a good EPC rating as one part of the picture, not a guarantee of year-round comfort. 

What can a survey actually tell you? 

A mortgage valuation is done for the lender’s benefit, not a detailed check of the property’s condition.4 Depending on the type and scope of survey you choose, a buyer’s survey may flag visible issues with the roof, windows, damp and ventilation, and may recommend a specialist look at heating, ventilation or energy performance. 

A standard survey typically won’t assess how hot the property gets in summer or test the performance of the heating and ventilation systems. If overheating is a concern for you, raise it with the surveyor before the inspection takes place. 

Building standards differ across England, Scotland, Wales and Northern Ireland, so if you’re looking at a newbuild or a recently altered property, check which requirements applied when the work was done and get local professional advice if needed. 

What could it cost to fix a hot home? 

That depends entirely on the property and the scale of the problem. Potential improvements include suitable blinds or curtains, external shutters or awnings, ceiling fans, better roof insulation, upgraded ventilation, solar-control glazing, an air-to-air heat pump, or fixed air conditioning. 

Some of this is straightforward. Some needs specialist installation, professional advice, or permission from a freeholder or local authority. Get proper quotations rather than assuming any of this will be cheap. 

Why this matters for your mortgage budget 

This heatwave is a good reminder that the purchase price and the monthly mortgage repayment aren’t the only costs of owning a home. A property that’s hard to keep cool could mean immediate spending on shading, ventilation or cooling equipment, and higher electricity bills during future hot spells. 

If you’re borrowing right up to the maximum available, you’ll have a lot less financial room to absorb those costs after completion. A lender’s affordability assessment tells you how much they’ll lend, not how much you should actually borrow once you’ve accounted for repairs, maintenance, energy costs and improvements. 

This is exactly where early mortgage planning helps. We can talk you through how different loan amounts, deposits and terms affect your monthly repayment, so you can work out how much you’re genuinely comfortable borrowing while keeping money back for the property itself. 

Our view 

Hotter summers are changing the way buyers should be sizing up their next home. Natural light, big windows and loft rooms are all appealing, but it’s worth thinking hard about whether those same features could make a property difficult or expensive to live in during a heatwave. 

Before you make an offer, look past the photographs, the floor plan and the EPC rating. Ask how the home actually performs in hot weather, check how well it can be ventilated and shaded, and factor in the cost of any improvements it might need. 

What a lender is willing to offer you isn’t necessarily what you should borrow. Leaving room in your budget for maintenance, adaptation and the unexpected can matter just as much as landing a competitive rate.