Tips to keep your home cool in a heatwave
How Do You Keep Your Home Cool In A Heatwave — Whether It's Victorian Or Brand New?
From loft hatches to ice-cold fans, here's what actually works — and why your house's age changes the rules.
UK Health Security Agency heat-health alerts are becoming a regular part of the British summer, and most homes — old or new — simply aren't built to cope. Do nothing and you're looking at sleepless nights, a spike in your electricity bill from fans and portable AC running round the clock, and — for anyone vulnerable, elderly, or with young children in the house — a genuine health risk. The good news: most of the fixes cost nothing at all. A few cost a little. None of them require ripping your house apart.
At Upcycle Interiors Ltd (UIL), we work on homes across Weymouth, Portland and Dorchester — plus the villages in between, from Charminster and Puddletown to Osmington, Sutton Poyntz and Bridport — and we see the full range, from 1890s cottages to last year's new-build estates. The advice for keeping them cool isn't the same. Here's what works for everyone, and then what's specific to your house's age.
The Quick Wins: Tips For Any Home
Close up in the day, open up at night. Keep curtains and windows shut on anything facing direct sun through the day — you're keeping the heat from a sauna out. Once the outside air is cooler than the inside (usually after sunset), throw everything open and let it flood through.
Create a through-draught. One open window does very little. Two windows on opposite sides of the house, open at the same time, will pull a genuine breeze through and clear the hot air that's built up all day.
Ice in front of the fan, properly. A bowl of ice — or a couple of reusable ice packs — in front of a fan works because the air passing over it picks up the cold as the ice melts, rather than just shifting warm air around the room. It's a small trick, but it makes a noticeable difference to a bedroom at 11pm.
Mind the loft hatch. This one catches people out. A loft space with the sun beating on the roof can hit temperatures well above the rest of the house — and if the hatch is left open during the day, that heat pours straight down into the room below. Keep it shut through the day, and open it in the evening once the loft has had a chance to cool, to let the trapped heat vent out.
Cook cold, cook outside, or cook late. An oven running at 4pm adds real heat to a kitchen that's already struggling. Cold meals, the barbecue, or simply waiting until evening all help.
Turn off what you're not using. Lights, laptops, chargers, the TV on standby — it all generates heat. LED bulbs run far cooler than older halogen or incandescent fittings if you haven't already made the switch.
Sleep low, sleep light. Heat rises, so the lowest floor of the house is usually the coolest place to sleep during a bad night. Swap the tog-heavy duvet for a light cotton sheet, and a lukewarm — not freezing — shower before bed helps your body cool down without shocking your system.
The building doesn't care what decade it was built in — it cares whether you're working with its design or against it.
Newer Homes: Fighting The Greenhouse Effect
Modern homes are built tight — great for keeping heat in over winter, and one of the reasons a new-build heating bill is lower than a Victorian one. In summer, that airtightness works against you. Building regulations introduced in 2022 now require new homes to be assessed for overheating risk at design stage, which tells you it's a recognised problem, not a myth.
A few things specific to newer properties:
Understand the delay. Well-insulated walls take longer for the day's heat to work through them — which means a new-build can feel fine at 4pm and stifling at 11pm, as the heat that soaked in at midday finally reaches the inside. Don't assume the house is cooling down just because the sun's gone in. Purge-ventilate properly overnight: windows open, ideally with a through-draught, for as long as it's safe to do so.
Check your trickle vents. Most new-build windows have small trickle vents built into the frame for background ventilation. Leave these open even when the main window is shut — they won't let much heat in, and they stop the house turning airtight and stuffy.
If you've got MVHR, use the summer setting. Homes with mechanical ventilation with heat recovery often have a "summer bypass" mode that stops the system recycling warm air. If you've never checked, it's worth five minutes finding the manual.
Watch the glass boxes. Large glazing, bi-fold doors and conservatories are brilliant for light and dreadful for solar gain — they behave like a greenhouse. External shading, blinds, or a good reflective film (more on that below) earns its keep here more than almost anywhere else in the house.
Don't run heat-generating appliances in the afternoon. Tumble dryers and dishwashers in a poorly ventilated new-build utility room add real heat to the house at the worst possible time of day.
If your loft or cavity insulation was fitted badly — soffit vents blocked, cavities not properly sealed — you get the worst of both worlds: cold in winter, hot in summer. That's a job worth having looked at properly rather than guessed at, and it's the kind of thing our property maintenance team gets called out for more than you'd think.
Victorian & Period Properties: Working With What The Victorians Knew
Here's the part that surprises people: a well-maintained Victorian house very often out-performs a modern one in a heatwave, and it's not an accident. Solid brick and stone walls have serious thermal mass — they soak up heat and release it slowly, acting almost like a storage heater in reverse. Suspended timber floors, old chimneys, and uninsulated solid walls all let a small amount of air move through the building even with the windows shut, which helps rather than hinders in summer.
Tips that work with a period property's design, not against it:
Use the sash properly. If your windows are original timber sash windows, they're built for exactly this. Hot air rises and escapes through a slightly opened top sash while cooler air draws in through the bottom — a design the Victorians relied on before anyone had heard of air conditioning. If your sashes have been painted shut or are too stiff to move, you've lost one of the house's original cooling features along with the draught-proofing benefits. Our guide to timber sash window restoration covers what's usually fixable.
Don't overdo the draught-proofing. Sealing a period property completely tight cuts winter drafts, but it also strips out the background ventilation that keeps it cool in summer. There's a balance to strike — our draught-proofing for traditional windows piece explains where that line sits.
Keep air bricks and vents clear. Landscaping, repointing, and flowerbeds creep over the airbricks at the base of solid-wall properties more often than you'd think. Blocking them stops the natural ventilation the house was designed around.
Shutters and blinds are period-appropriate, not just practical. Many Victorian houses originally had external shutters, awnings or canopies specifically to block solar heat before it hit the glass. Reinstating something similar — subject to conservation rules if you're in a listed building or conservation area — is both authentic and effective. Our Period Property Preservation team can advise on what's appropriate for your property.
Mind the render and stonework. Damaged, dark, or poorly maintained external render and stonework absorbs more heat than sound stonework in good condition. If yours is due some attention anyway, our guide to repairing painted external stonework on Victorian-era homes is worth a read.
The loft rule still applies. Older lofts often have insulation added piecemeal over the decades, with no thought given to ventilation. Same principle as above: hatch shut in the day, open once the loft's had a chance to cool at night.
A Few Things Worth Buying
None of this requires a full renovation. A handful of well-chosen products make a real difference for not much outlay:
Heat-reflective window film — rabbitgoo Heat Reflective Window Film, Amazon's Choice, 4.1★ (61,931 ratings). Particularly worthwhile on south or west-facing windows, large new-build glazing, or conservatories. Blocks a significant share of solar heat and UV without losing the light.
Thermal-lined blackout curtains — PONY DANCE Grey Blackout Thermal Curtains, Amazon's Choice, 4.5★ (50,795 ratings). Block far more heat than a standard pair, without changing how a period room looks from the outside.
A decent pedestal fan — Levoit Standing Fan, 4.6★ (2,706 ratings), oscillating with a timer. Combined with the ice-pack trick above, still one of the cheapest ways to cool a bedroom.
Reusable ice packs — Comfytemp 6-Pack Mini Gel Ice Packs, Amazon's Choice, 4.5★ (2,774 ratings). Less mess than a melting bowl of ice cubes, and they go straight back in the freezer for tomorrow night.
A digital max/min thermometer and hygrometer — ThermoPro TP49, 4.5★ (37,200 ratings). Useful for tracking exactly how hot a room gets overnight, especially with young children, pets, or anyone vulnerable in the house.
A cooling mattress topper — Zinus Double Cooling Mattress Topper, bamboo cooling topper, 4.3★. Pairs well with lightweight cotton bedding for the nights when nothing else quite cuts it.
A portable air conditioning unit — AuraHome 9000 BTU 4-in-1, 4.3★, 400+ bought last month. The last resort rather than the first, given the running cost, but worth having for the one room where nothing else is enough.
Loft insulation roll — BLOSTM Multi-Purpose Foil Insulation Roll, Best Seller, 4.6★ (1,700 ratings). Worth pairing with a proper check of your loft ventilation rather than just piling it in.
The Bottom Line
Whether your house was built in 1895 or 2024, the same principle holds: work with how it was designed to behave, not against it. Old houses want you to let their mass and their airflow do the work. New houses want you to fight their airtightness with proper night-time ventilation. Get either wrong, and you're just paying to move hot air around a room.
The best cooling system in your house is usually the one you're not using properly.
Mark & the UIL team
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References
UK Health Security Agency — How to keep cool and stay well during hot weather: https://ukhsa.blog.gov.uk/2026/06/23/how-to-keep-cool-and-stay-well-during-hot-weather/
Met Office — Tips for keeping cool in hot weather: https://www.metoffice.gov.uk/blog/2026/met-office-tips-for-keeping-cool-in-hot-weather
NHS — Heatwave: how to cope in hot weather: https://www.nhs.uk/live-well/seasonal-health/heatwave-how-to-cope-in-hot-weather/
British Red Cross — How to keep your home cool in a heatwave: https://www.redcross.org.uk/get-help/prepare-for-emergencies/heatwaves-uk/advice-and-tips/keep-home-cool
The Conversation — Heatwaves: five reasons why Victorian houses are cooler than modern buildings: https://theconversation.com/heatwaves-five-reasons-why-victorian-houses-are-cooler-than-modern-buildings-283934
