How to Keep Your Home Cool During a UK Heatwave
When temperatures climb, the way you manage your windows, shading and ventilation can make a surprising difference. Longer-term improvements can make your home considerably more comfortable too.
A hot British summer used to mean opening the windows, putting a fan on and enjoying the sunshine.
For many homeowners, it is no longer quite that simple.
The summer of 2026 has already brought repeated periods of unusually hot weather. By mid-July, the Met Office reported that the UK had experienced three official heatwaves, with unusually warm nights also limiting the ability of buildings to cool down between hot days.
And that is when many people discover something about their homes:
British houses can be remarkably good at getting hot — and staying hot.
Fortunately, there are things you can do immediately to make conditions more comfortable, followed by more permanent improvements that can make the property better prepared for future hot summers.
1. Keep the Sun Out Before the House Gets Hot
One of the most effective approaches is also one of the simplest.
Stop excessive solar heat entering the house in the first place.
Windows receiving direct sunlight can introduce a substantial amount of heat into a room.
During the hottest part of the day, close blinds or curtains on windows exposed to strong sunshine. Current Met Office and UK health guidance specifically recommends shading sun-facing windows to help prevent heat building up indoors.
Pay particular attention to:
South-facing windows
West-facing windows during the afternoon
Large patio and bifold doors
Rooflights
Conservatories
Highly glazed extensions
If one part of your home consistently becomes much hotter than everywhere else, sunlight through glazing may be a major contributor.
2. Don't Automatically Open Every Window
This can feel completely wrong.
It is hot, so surely opening all the windows must cool the house?
Not necessarily.
If the temperature outside is significantly higher than the temperature inside, opening windows can simply allow hotter air into the property.
During the hottest period of the day, it can therefore be better to keep windows closed where the interior is cooler than outside.
Then, as the outside temperature drops during the evening and overnight, open windows to release accumulated heat and encourage cooler air through the property.
The Met Office currently recommends this approach during hot weather.
The principle is simple:
Keep hot air out during the hottest part of the day and bring cooler air in when outdoor temperatures fall.
3. Create Cross-Ventilation When It Is Cooler Outside
When conditions allow, opening windows on opposite sides of the home can encourage air to move through the building.
This is usually far more effective than opening one window in a closed room.
If you have:
Front and rear windows
Windows on different elevations
High- and low-level openings
Rooflights
A stairwell connecting different floors
you may be able to create useful natural airflow.
Opening higher-level windows or rooflights can also help warmer air escape.
The best time to purge accumulated heat is often during the evening, overnight or early morning when outside temperatures have fallen.
Security must obviously be considered when leaving windows open overnight.
4. Use Your Curtains and Blinds Strategically
Not all windows need to remain covered all day.
Follow the sun.
A window that receives strong morning sunshine may need shading earlier in the day, while west-facing glazing can become a much greater problem during the afternoon and early evening.
The objective is not to turn your home into a dark box.
It is to shade the glass when direct sunlight is creating unwanted heat.
Once the sun has moved away, you may be able to reopen the blinds without significantly increasing the room temperature.
5. External Shading Can Be Even More Effective
Internal curtains and blinds help, but the sunlight has already passed through the glass before reaching them.
Stopping direct sunlight before it reaches the window can therefore be particularly effective.
Options can include:
Retractable awnings
External blinds
Shutters
Pergolas
Brise-soleil
Covered terraces
Carefully positioned trees
Deciduous planting
The last option is particularly interesting.
A deciduous tree can provide useful shade during summer when it is in leaf while allowing more sunlight through during winter after the leaves have fallen.
Good landscape design can therefore play a small but useful role in controlling summer temperatures.
6. Keep Internal Heat Generation Down
Your home also generates heat internally.
During very hot weather it can be worth considering which appliances are adding unnecessary heat.
Ovens are an obvious example.
So are tumble dryers.
Computers, televisions, lighting and other electrical equipment also produce heat.
One laptop is unlikely to transform the temperature of a house, but a home office containing several computers and monitors can become noticeably warmer.
During a heatwave, reducing unnecessary internal heat helps the building stay cooler for longer.
7. Use Fans to Improve Personal Comfort
Fans do not normally lower the actual temperature of a room.
What they can do very effectively is move air across the body, helping occupants feel cooler.
Ceiling fans can be particularly useful in bedrooms and living areas because they move relatively large volumes of air while taking up no floor space.
Portable fans provide a quick alternative.
But fans should be regarded as part of the cooling strategy, not necessarily the complete solution to serious overheating.
8. Think About the Upstairs Differently
The hottest part of many British homes is the upper floor.
Heat rises through the property, while upstairs rooms may also receive additional heat through the roof.
This can make bedrooms particularly uncomfortable.
During a prolonged heatwave, it may be useful to concentrate your cooling strategy on the rooms that actually matter overnight.
For example, rather than attempting to cool an entire house, the priority might be:
Can we make the bedrooms comfortable enough to sleep in?
That can change the type of solution required.
9. Loft Rooms Need Particular Attention
Loft conversions can be fantastic additions to a home.
They can also become extremely hot.
The room sits directly beneath a roof exposed to solar radiation for much of the day, while roof windows can contribute additional solar gain.
If a loft room regularly becomes uncomfortable, consider the complete construction:
Roof insulation
Roof windows
Solar-control glazing
Blinds
External shading where appropriate
Opening ventilation
Mechanical ventilation
Air conditioning
Simply adding a more powerful fan may be addressing the symptom rather than the cause.
10. Insulation Can Help Keep Heat Out Too
Insulation is normally marketed as something that keeps homes warm.
But its basic function is slowing heat transfer.
Good roof and wall insulation can therefore help reduce how quickly external heat travels into a property during hot weather, as well as reducing heat loss during winter.
That gives insulation a potential year-round comfort benefit.
However, insulation needs to work alongside appropriate ventilation and solar control.
A well-insulated building can still overheat if large amounts of unwanted solar energy enter through glazing and there is no effective method of removing accumulated heat.
11. Large Areas of Glass Need Careful Thought
Over recent years, homeowners have embraced:
Large bifold doors
Sliding glass walls
Roof lanterns
Rooflights
Full-height windows
These features can create beautiful, light-filled rooms.
But they can also introduce significant solar heat.
The answer is not to stop using glass.
It is to design glazing intelligently.
Orientation, glass specification, shading, opening sections and ventilation all matter.
If you are planning an extension now, it is worth asking:
What will this room feel like on a 35°C afternoon?
That question can be just as important as asking how much daylight the room will receive.
12. Could Air Conditioning Be the Right Solution?
Sometimes passive measures will not completely solve the problem.
A south-facing loft bedroom or heavily glazed extension may simply require cooling during the hottest periods.
Modern domestic air conditioning provides an increasingly practical option.
And there is an important distinction between cooling one problematic room and installing air conditioning throughout an entire house.
A targeted system might serve:
A principal bedroom
Loft conversion
Home office
Garden room
Kitchen extension
Main living space
For many properties, this could provide the comfort homeowners want without trying to mechanically cool every room.
13. Modern Air Conditioning Can Heat as Well as Cool
Many modern domestic air-conditioning units are actually reversible air-to-air heat pumps.
They can cool the room during summer and provide heating during cooler periods.
That changes the economics considerably.
Instead of installing equipment that might only be useful during a handful of hot weeks, homeowners can potentially use the same system at other times of the year.
This is why cooling should increasingly be considered alongside the home's overall heating and energy strategy.
14. Solar Power Can Help Pay for Summer Cooling
There is a particularly attractive relationship between solar panels and air conditioning.
When do you normally want the most cooling?
When the sun is shining.
And when does a solar PV system have the opportunity to generate strongly?
When the sun is shining.
That creates the possibility of using electricity generated by your own roof to operate cooling during hot sunny periods.
A well-designed home energy system might ultimately combine:
Solar PV
Battery storage
Air conditioning
Efficient heating
Smart controls
EV charging
Hot-water management
The objective is not simply to generate electricity.
It is to use the electricity intelligently.
15. Battery Storage Can Extend the Benefit Into the Evening
One of the problems with overheating is that the house may remain uncomfortable after the sun has gone down.
Solar generation is falling just as occupants return home or prepare for bed.
Battery storage can potentially help bridge that gap.
Surplus electricity generated earlier in the day can be stored for use later.
Whether a battery makes financial sense depends on the property, electricity consumption, solar installation, tariffs and lifestyle.
But this is exactly why individual green technologies should not always be considered in isolation.
16. Smart Controls Can Help the Home Respond Automatically
Increasingly, homeowners can automate how their property responds to changing conditions.
Smart technology might control:
Motorised blinds
Heating
Air conditioning
Ventilation
Battery charging
EV charging
Hot water
Energy consumption
Temperature sensors can identify when particular rooms are overheating.
Smart blinds could close automatically.
Cooling can be concentrated where it is actually required.
Solar energy can be directed towards useful loads when generation is available.
The home begins to manage energy rather than simply consume it.
17. What Should You Do During a Heatwave?
If the temperature is climbing today, start with the simple measures:
Shade windows receiving direct sunlight.
Keep windows closed where it is hotter outside than inside.
Open windows when the outside air becomes cooler.
Encourage cross-ventilation where practical.
Reduce unnecessary internal heat from appliances.
Concentrate fans and cooling on the rooms you are actually using.
Use cooler overnight temperatures to purge heat from the property.
Official NHS advice also stresses the importance of keeping hydrated, avoiding excessive exposure to the hottest part of the day and taking additional care of older people, young children and those vulnerable to heat.
Then Look at What the Heatwave Has Taught You
This is perhaps the most useful part.
When the hot weather eventually disappears, don't forget which parts of your home struggled.
A heatwave is effectively a real-world test of your home's summer performance.
Make a mental note.
Which rooms overheated?
At what time?
Which windows received strong sunlight?
Did the loft remain hot overnight?
Did the extension become unusable?
Could you create enough ventilation?
Did the blinds make a noticeable difference?
Would external shading have helped?
Those answers provide valuable clues about which permanent improvements might be worthwhile.
Don't Simply Buy the First Solution
If your bedroom gets hot, buying an air-conditioning unit may solve the problem.
But perhaps better roof insulation and solar-control measures are required as well.
If your extension overheats, the answer could be shading rather than more cooling.
If you are already considering solar panels, adding efficient cooling might make considerably more sense as part of the same energy strategy.
And if your entire house becomes uncomfortable, the property may need a broader look at glazing, insulation and ventilation.
Start with the problem — then choose the technology.
A Cooler Home Can Also Be a Better Home
Preparing a property for hotter summers does not have to be simply another expense.
Many of the improvements can provide benefits throughout the year.
Better insulation can reduce winter heating demand.
Solar panels can reduce purchased electricity.
Air-to-air heat pumps can provide heating as well as cooling.
Smart controls can reduce wasted energy.
Shading can make rooms considerably more comfortable.
And thoughtful improvements can create a home that simply feels better to live in.
That is ultimately what a green-home strategy should achieve:
greater comfort, better energy efficiency and lower unnecessary energy consumption.
NEXT STEPS
If this summer has shown you that parts of your home are becoming too hot, now is a good time to understand why before simply buying another fan or choosing a cooling system.
APN Green Homes can look at your property as a whole and help identify practical ways of improving summer comfort, winter warmth, energy efficiency and running costs.
The right solution could involve something simple, or it could involve combining several technologies so they work together.
Choose the option below that suits you.
BOOK A GREEN HOME SURVEY
Get a detailed assessment of your property and practical recommendations covering areas such as overheating, insulation, glazing, ventilation, shading, heating, air conditioning, solar PV, battery storage and smart controls.
BOOK A PHONE CONSULTATION
Talk through the rooms that are overheating, your property and any improvements you are already considering. We can help you identify the most sensible next step. Find Out More →
EMAIL US
Send us details of your home, photographs and the problems you are experiencing and we can advise you on the appropriate way forward. Email: team@apngreenhomes.co.uk
GIVE US A CALL
Prefer to talk it through? Give us a call, tell us what is happening in your home and what you would like to achieve. Tel: 0370 042 2021
Don't just make your home cooler for the next heatwave. Make it more comfortable and efficient throughout the year.
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