I’ve begun shutting the curtains earlier to cut energy use, and one thing makes a big difference to how well it works

This is a well-tested trick, but its effectiveness varies. Here’s why

As the evenings get darker and the temperature falls, I’m keen to try any energy-saving habit that can help keep my bills down. But does closing the curtains early really reduce energy use at home?

That question matters more than ever, especially after energy prices rose and more increases are expected in the near future.

Martin Lewis has long recommended drawing the curtains as soon as the sun sets. If you still need convincing, I’ve been trying it again at home recently, and here’s what I found.

Does closing your curtains early save energy?

Yes, closing your curtains early can save energy. It helps block draughts and cuts heat loss through your windows, which can make your home feel warmer. That means you may be less likely to turn on the central heating for an extra hour or reach for an electric heater or oil-filled radiator.

Best of all, it costs nothing.

“Closing your curtains at dusk is a simple way to help keep your home warm as temperatures drop,” says Stuart Middleton, So Energy’s Consumer Energy Expert. “Windows can be a source of heat loss, so drawing your curtains creates an additional layer of insulation that helps slow the rate at which heat escapes. Thick, well-fitting or thermally lined curtains can be particularly effective.

“The amount of energy you could save will depend on your windows, the type of curtains you have and how well insulated your home is, so it’s difficult to put an exact figure on the savings from this habit alone. However, it’s a simple, low-cost change that can help keep your home comfortable during the colder months without relying as heavily on your heating.”

I can also confirm that the idea works. I’ve used this curtain-closing habit for a long time, and the house definitely stays warmer for longer in the evening without needing another hour of heating.

When I measured the temperature in front of my closed curtains and behind them, I found a 2°C difference after sunset, especially in rooms with thermal curtains. If the curtains had been open, the room would have been noticeably colder.

When should you close your curtains to save energy?

To get the most from this method, close your curtains shortly before it gets dark. Setting a reminder for late afternoon is a simple way to remember to do it at the right time.

Doing this lets you make the most of any solar gain during daylight and helps retain heat once the sun has gone down and temperatures start to fall.

If you’re usually at home around then, a phone reminder is an easy way to make sure you close the curtains at the ideal time. But what if you aren’t?

In that case, you can automate the process. A device such as the SwitchBot Curtain 3 (£99.99) lets you schedule your curtains to open and close exactly when you want, whether you’re home or not.

Ideal Home’s Digital Editor Becky has been using one for the past few months: “I added the SwitchBot Curtain 3 to my living room curtains a few months ago and used the schedule function to help control the temperature in my home. In summer, I scheduled them to open when it was cooler and close during the hottest parts of the day. Now for autumn and winter, I’ve adjusted the schedule so that they close as soon as it gets dark at night to keep the cold out and ensure I always come home to a cosy space.”

SwitchBot

Switchbot Curtain 3

If you’re unlikely to be home at sunset, automating your curtains is a smart way to get the benefits of this hack.

Aqara

Curtain Driver E1 - Track Version

This curtain driver includes a built-in light sensor, so it can operate automatically based on the brightness outside.

Aqara

Roller Shade Driver E1

If you have roller blinds instead of curtains, you can still automate opening and closing with this compact device.

Does the type of window covering matter?

In my experience, the type of window treatment you use makes a big difference to how warm a room stays once the curtains are shut.

At home, I have a mix of thermal curtains, blinds, fabric blinds, wooden blinds and standard curtains, and there is a clear difference in how well each one traps heat.

For me, the strongest performers are thermal curtains and blinds, followed by wooden blinds, while standard curtains and fabric blinds come last. Even though winter is still some way off, I saw a 2°C difference in front of and behind my thermal curtains and blinds, just under 1°C with wooden blinds, and around half a degree with standard curtains.

Luckily, in the rooms where I spend the most time, I already have Berlin blackout and thermal curtains from Dunelm, starting from £15. I’ll definitely be replacing the standard curtains in my guest room before long.

Dunelm

Berlin Blackout Thermal Eyelet Curtains

I use these blackout and thermal curtains from Dunelm in my bedroom, living room and kitchen, and they do an excellent job of helping regulate the temperature in both warm and cold weather.