I keep my curtains closed in a heatwave, but my home never feels cave like — this is how I’ve found the balance between temperature regulation and light ingress

This summer has been a test on the majority of our homes. Unlike previous heatwaves which can be over in a few days, the prolonged 35+º heat for weeks on end really has been something else.

However, without the infrastructure to cool our homes, we’re all stuck with the windows closed and the curtains drawn during the day to keep the hot air outside and the solar gain to a minimum. These passive cooling strategies have been tried and tested for centuries and are a good way to keep energy usage down while limiting the use fans or air conditioners. But, in a prolonged heatwave like we've seen this summer, saving energy and keeping your house cool can also mean it feels like you live in the dark.

While my house has certain features that help it feel cool in the summer, it can still get really hot when a heatwave hits. As I work from home, I've had to keep the curtains closed to maintain a comfortable temperature, but I’ve also tried to come up with ways to make our living spaces feel brighter and less cave like.

1. I use bamboo blinds for dappled light

We have a downstairs bathroom that thankfully faces north. Now, normally we wouldn’t think twice about this space getting too hot, but with the lengthy heatwave, I’ve found having our bamboo blinds closed during this time still lets in a good amount of light. Certainly enough to put on makeup without looking like a clown!

This makes absolute sense, especially when you consider countries like China, Indonesia and India have all been using bamboo to shade their interior spaces for centuries. And as our climate is warming up for what looks to be the foreseeable, we should be taking note of how traditionally hotter regions mitigate overheating.

Ours were really cost efficient as they were a last-minute purchase after our bathroom was finished, but I wish I had researched ones that were treated for moisture as ours are now looking a bit worse for wear from the room's humidity.

Thermal blinds with a honeycomb weave have become a much recommended product to allow light, but not heat into a shaded room. 'Slatted blinds and shutters are also particularly useful because they can be angled upwards, ' adds Caroline Montague at Villa Sartiano. 'That blocks the direct beam but still sends some daylight towards the ceiling, which gives the room a much softer brightness.'

Caroline Montague

Caroline Montague has been an interior designer for 30 years and has a special focus on designing homes in Italy, alongside her own retreat.

2. I added voile curtains for diffused light

To diffuse harsher sunlight, we use voile curtains alongside thicker ones for nighttime in our bedroom. Now, I know they have a bad rep from our nans’ houses where net curtains made every room feel gloomy and dated, but there are some gorgeous modern designs to be found that bring a more Parisian elegance to this fabric.

The game-changer for us when it is hot, is that we bought thermal voile curtains so the rate at white the indoor temperature rises is slowed down. This also works the opposite way in the winter.

3. I track the sun’s progression over my house

One of the first things we did when we moved into our house was to take note of where the sun begins its day and where it is positioned at the hottest parts. At the time it was to plan our renovation, but I have found it super useful so we can open and close curtains when I know the sun has moved round.

'After more than 30 years of designing homes, one thing I have learnt is that a house rarely overheats evenly,' explains Caroline Montague 'Follow the sun around the building rather than closing everything at once. An east-facing room may need its curtains drawn early in the morning, while a west-facing room often becomes much hotter later in the afternoon.'

A basic timeline would look like this:

• 7am: West and south-facing curtains open, east-facing closed
• 12pm: East and west open, south closed
• 3pm: West and south closed, east open

I generally don’t worry about our north-facing window as this is a great source of constant diffused light.

4. I'm strategic about the positioning of mirrors

Having the curtains closed all of the time can really affect the mood of the house and too much artificial light can serve to make a space feel dour, especially when overhead lights and table lamps are on during the day while working from home.

'The key is to control how daylight enters and bounces around the room,' says Chloe Barrow, Head of Creative Interiors at Laura James. 'I would avoid placing mirrors directly opposite sunny windows during a heatwave, as they simply bounce the heat deeper into the house. It’s better to place them on perpendicular side walls to catch ambient light, without bringing the heat in.'

Using the pattern from the point above, you can do what we do and strategically place mirrors to reflect the light into rooms that are currently shaded. For instance, the north-facing light of our utility is near a large mirror in the otherwise dark hallway. It allows the light to bound around the space and make it feel much less gloomy.

Chloe Barrow

Interior expert Chloe Barrow leads on interior trend forecasting, and the creative direction of home and garden products at Laura James Home. With a background in fashion, business, and e-commerce, she’s delivered key campaigns for brands like Marks & Spencer, blending interior style insight with commercial strategy across both digital and retail spaces.

5. I combine internal measures with external shading

Now, if having your curtains closed during the day is simply too much for you to take, external shading might be a better option. Although this isn’t my first port-of-call, I get it; we spend all year waiting for warm and sunny days and the last thing you want to do is shut yourself away from it all.

So, if you really want to have the curtains open during they day, look to what you can do to the exterior of your house to prevent overheating. One such element we love in for our west-facing patio door that don’t have curtains or blinds is to use natural planting either side of the doors.

Sail shades can also be installed so come light passes through, but the harsh direct sun is diluted a bit. Retractable awnings work much the same, but you can also get mini versions for above windows. This is especially good for home offices.

'Awnings are a brilliant investment as they stop heat before it even hits the glass, without making the room look dark and dreary,' says Chloe Barrow. 'You’re still getting a lot of light, but less heat.'