Your House Survived This Summer. Will It Survive the Next Heatwave Better?

“The worst possible time to start preparing your house for a heatwave is when the bedroom is already 30°C.”

October brings a familiar list of household jobs: check the heating, clear the gutters and find the warmer bedding. Preparing for next summer rarely makes the list.

Yet this is an excellent time to ask what the last spell of hot weather taught us.

Which room became unbearable? Which window caught the afternoon sun? Did opening everything actually help? Why was the bedroom still hot long after the garden had cooled?

Once cooler weather arrives, it is tempting to forget those uncomfortable nights. But the next heatwave may arrive before we have chosen an awning, booked an installer or planted a tree.

Autumn gives us time to turn a summer problem into a practical improvement.

Europe’s Hot Summers Give Us a Reason to Prepare

A rapid analysis published in September 2025 by researchers at Imperial College London and the London School of Hygiene & Tropical Medicine estimated around 24,400 heat-related deaths across 854 European cities during summer 2025. Approximately 16,500 were attributed to human-induced climate change.

These were modelled estimates, rather than a complete count of recorded deaths across Europe. The cities represented around 30% of Europe’s population, and the researchers acknowledged limitations in their data and assumptions. Nevertheless, the findings underline why overheating deserves serious attention. lshtm.ac.uk

For homeowners, the useful response is to identify improvements that make everyday life safer and more comfortable.

We can reduce emissions while also adapting our homes to the heat already affecting us.

1. Give Your House a Summer Report Card

Before buying anything, write down what happened during hot weather.

• Which rooms became hottest?
• At what time did they become uncomfortable?
• Did afternoon sunshine make a bedroom particularly difficult?
• Did rooflights or a conservatory admit strong sunlight?
• Could you ventilate safely after dark?
• Was there a cooler room available for sleeping?

Next summer, use simple thermometers in the bedroom and living room, positioned away from direct sunshine. An outdoor thermometer should also be shaded.

Record temperatures before breakfast, during the afternoon and at bedtime.

Practical example: A bedroom that becomes hot immediately after afternoon sunshine may need better window shading first. A room that remains hot throughout the night also needs an effective way to release accumulated warmth.

Measurements turn “the whole house was dreadful” into a problem you can investigate.

2. Stop Sunshine Before It Reaches the Glass

External shading intercepts sunlight before it enters the home.

Internal curtains and blinds remain useful, but external awnings, shutters and blinds can prevent more solar heat from getting inside. Adjustable shading also allows you to admit useful sunshine during colder weather. BBSA

Possible improvements include:

• A retractable awning over exposed patio doors.
• External shutters on a troublesome bedroom window.
• External roller blinds.
• Suitable external shading for rooflights.

Start with the window causing the greatest difficulty. One carefully chosen improvement may be more useful than buying identical blinds for every room.

Practical example: A west-facing bedroom receives low afternoon and evening sunshine. A shallow overhead canopy may miss much of it, so adjustable external blinds or shutters may suit that situation better.

Ask suppliers a specific question:

“How will this shade my window at the time of day when overheating is worst?”

Also ask about wind limits, maintenance, fixings and whether windows can still open.

3. Close Blinds Before the Room Becomes Hot

When external shading is impractical, make better use of internal curtains and blinds.

Close them before direct sunshine reaches the window. Suitable reflective blinds can help where external products cannot be installed. BBSA

There is a familiar trap here: a bright room feels inviting, so we leave everything open. Several hours later, we notice that it has become uncomfortable.

By then, the floor, furniture and walls may already have absorbed warmth.

Shading works best as prevention.

During the next hot spell, make closing the relevant blinds part of the morning routine. The right timing depends on which direction each window faces.

4. Insulation Belongs in the Summer Conversation

We usually associate insulation with keeping warm.

However, insulation slows heat transfer. It can also help limit heat entering through a hot roof during summer. Energy Saving Trust

The important qualification is that insulation cannot remove heat already inside.

Sunshine through windows, cooking and electrical equipment still add heat. A well-insulated home therefore needs suitable shading and ways to release accumulated warmth. Historic England warns that energy-efficiency improvements without adequate ventilation or cooling can contribute to overheating. Historic England

Practical example: If an upstairs bedroom is uncomfortable, ask an installer to consider roof heat, window exposure and ventilation together. Adding insulation alone may leave the main cause unresolved.

Do not block designed roof ventilation when insulating a loft. Roof rooms and older buildings need advice suited to their construction.

Think about winter warmth and summer comfort as parts of the same improvement project.

5. Open Windows According to Temperature

“Open all the windows” is an incomplete heatwave strategy.

When outdoor air is hotter than indoor air, opening windows can bring heat inside. When outdoor air becomes cooler, ventilation can help remove accumulated warmth.

UKHSA advises keeping sun-facing rooms shaded and opening windows when it is cooler outside, provided this is safe. UK Health Security Agency

Consider this illustrative example:

Time	Outside	Bedroom	Useful response
Afternoon	33°C	27°C	Keep solar heat out; avoid admitting hotter outdoor air.
Late evening	21°C	28°C	Ventilate safely to release accumulated heat.

Where possible, openings on different sides of the home can encourage airflow.

But the plan must work for the people living there. Consider security, children, pets, noise and outdoor air quality. Never prop open fire doors to create a breeze.

If you have mechanical ventilation, learn what its summer settings actually do. A summer bypass is not air conditioning.

October is a good time to work out which windows can safely provide useful ventilation.

6. Plant Shade for Future Summers

A tree is a long-term improvement, rather than an instant cure for next July.

A suitably positioned deciduous tree can provide summer shade while allowing more sunlight through its bare branches in winter. Climbers on a well-designed pergola can also shade seating areas or exposed glazing.

Choose for the mature plant, not the size in the nursery pot.

Consider available space, roots, drains, neighbouring properties, maintenance and water needs. At my own home, I would also consider how future growth might shade the solar panels.

Plan during autumn and winter, then plant at a time appropriate to the species, soil and conditions. Provide the care needed for establishment, particularly during dry weather.

The useful question is:

“Where will this plant cast its shadow when I need it?”

A tree in the wrong place may provide little useful shade. Thoughtful positioning makes the difference.

7. Reduce the Heat You Generate Indoors

Shading cannot solve every problem if we keep adding heat inside.

UKHSA recommends switching off non-essential electrical equipment, while government guidance also suggests considering cooking at cooler times of day. UK Health Security Agency

In practice, that might mean:

• Choosing meals requiring less oven use.
• Switching off unused computers and equipment.
• Reducing unnecessary lighting.
• Using a cooler room for work during the hottest hours.

In a home classroom, office or studio, this deserves particular attention. Lights, computers and other equipment can make a busy room uncomfortable.

My own investment in solar panels, batteries, insulation and a heat pump has made me think carefully about energy. Summer comfort adds another question:

Where is that energy becoming heat?

Solar electricity can support cooling. Preventing avoidable heat gain can reduce the cooling required.

8. Identify Your Coolest Room

A heatwave plan should identify the coolest usable room, especially for sleeping.

Could a downstairs room become a temporary bedroom? Should one exposed window receive shading first because someone particularly vulnerable sleeps there?

Government guidance identifies older people, young children and people with certain health conditions among those at greater risk. It also recommends moving to a cooler part of the home where possible. GOV.UK

Include relatives or neighbours who may need help operating blinds, windows or cooling equipment.

Passive measures may be insufficient during prolonged heat, particularly when nights remain warm. If overheating persists, seek advice on suitable active cooling, including running costs, noise and installation requirements.

Do not assume an existing heating heat pump can cool the home. The unit, controls and heat emitters must support it. Some air-to-air heat pumps can provide both heating and cooling. Energy Saving Trust

Your October-to-Summer Action Plan

When	Practical action
October	Review the hottest rooms and identify the main problem window.
Autumn and winter	Compare shading options, seek insulation advice and plan planting.
Before committing to work	Check permissions and landlord agreement where relevant.
Spring	Fit agreed improvements and test blinds, windows and ventilation.
Before hot weather	Identify the coolest room and agree a household routine.
During the next heatwave	Measure temperatures, shade early and ventilate when outdoor air is cooler.

For a limited budget, begin with a thermometer, effective shading on the worst window and a better ventilation routine.

Renters can document overheating and raise it with their landlord while making appropriate reversible improvements.

Make Next Summer Easier Now

We would rarely wait until the coldest night of winter to wonder whether the heating works.

Summer comfort deserves the same preparation.

October offers time to notice, compare, budget and arrange work. A blind can be fitted. An awning can be chosen carefully. A tree can begin establishing. A ventilation routine can be agreed before everyone is tired and uncomfortable.

We cannot promise that every home will stay cool through every heatwave. We can make practical improvements that give it a better chance.

When the next hot spell arrives, will your house simply endure it again—or will the work you begin this autumn make life inside it better?