I’m Closing My Curtains Early To Save Energy — This Impacts How Well The Hack Works

TL;DR

Before you orderOffer from Amazon

Get cleaning gear delivered free with Prime

• Fast, free delivery on millions of items
• Prime Video, Amazon Music and more included
• Member-only deals all year

Start your free Prime trial →Free trial for eligible customers · Cancel anytime

As an affiliate, we earn on qualifying purchases.Hide

An Ideal Home report says closing curtains just before sunset can reduce heat loss through windows and may help homes stay comfortable without extra heating. Its writer measured temperature differences behind several window coverings, but the report gives no controlled test or estimate of bill savings.

An Ideal Home writer reported that closing curtains before sunset left the area behind thermal window coverings warmer than the room-facing side, highlighting a low-cost way to reduce heat loss through glazing. The report includes temperature readings from one home, but does not establish how much energy or money households can save.

The writer said they measured a 2°C difference in front of and behind thermal curtains and blinds after sunset. The reported gap was just under 1°C for wooden blinds and about half a degree for standard curtains. These are readings from the writer’s home, not results from a controlled test or a broad household survey.

Stuart Middleton, So Energy’s consumer energy expert, said windows can be a source of heat loss and that drawing curtains adds a layer of insulation that can slow it. He said thick, well-fitting or thermally lined curtains can be particularly effective. The report does not give a measured reduction in heating use or a monetary saving.

The writer recommends drawing curtains just before it gets dark, rather than leaving them open after sunset. That timing is intended to allow daylight to warm the home before reducing heat loss in the evening. The report suggests checking local sunset times; an automated curtain device is another option for people who are away at that time.

How Curtains May Limit Heat Loss

Windows can allow heat to escape, so adding a barrier at dusk may help a room retain warmth. If a home feels comfortable for longer, occupants may be able to delay turning on the heating or avoid using a supplementary electric heater for as long. That is a possible effect, not a guaranteed bill reduction: the report provides no energy-meter data to show that heating use actually fell.

The approach costs nothing if curtains are already installed, but the result varies with the home. Window type, curtain fit, fabric and insulation all affect performance. The reported temperature differences can help explain why thermal coverings may feel more effective, but they do not show that every room will see the same result or that the temperature gap translates directly into a specific saving.

For households trying to manage heating costs, the advice is best treated as a modest measure alongside other practical steps, rather than a substitute for heating or home insulation. The source describes energy-price rises as a reason for renewed interest in ways to reduce consumption, but offers no cost calculation tied to curtain use.

The Sunset Timing Test

The Ideal Home report revisits advice attributed to Martin Lewis to close curtains as soon as the sun goes down. Its writer said they had used the habit before and restarted it over the week leading up to the report. They described the home as feeling warmer for longer in the evening, but this is a personal observation rather than a measured comparison of heating bills.

In the example given, sunset was forecast for 4:52 p.m., and the writer set a reminder to close the curtains at about 4:30 p.m. Sunset time changes by location and date, so the example is not a universal schedule. Closing curtains before nightfall is presented as a way to make use of daytime solar warmth while limiting later heat loss.

The report also notes that window coverings performed differently in the writer’s home: thermal curtains and blinds produced the largest measured difference, followed by wooden blinds, then standard curtains and fabric blinds. The article mentions automated curtain devices as an option for scheduled opening and closing, but does not report a comparative test of those products or their cost-effectiveness.

“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.”

— Stuart Middleton, So Energy’s consumer energy expert

Savings Depend on Each Home

The report does not establish how much energy or money closing curtains saves. Its temperature readings come from one home, and the article does not provide details such as measurement equipment, room conditions, window construction, heating settings or a comparison against an otherwise identical evening with curtains left open.

It is also unclear how much the reported temperature differences changed the home’s heating use. Results may vary with glazing, draughts, curtain coverage, installation and the building’s overall insulation. No independent test or broader dataset is included, and the source does not quantify the effect of automated curtains compared with closing them manually.

Try the Habit at Home

Readers can use their local sunset time to set a reminder and close curtains shortly beforehand, then observe whether rooms remain comfortable for longer. The report offers no formal follow-up study or promised update, so any household assessment should distinguish a subjective feeling of warmth from a measured change in heating use.

For a clearer estimate of financial impact, households would need to compare heating consumption under similar weather and thermostat conditions over more than one evening. The report’s main practical point remains limited: curtains may reduce heat loss at windows, but the size of any saving is not established.

Key Questions

Does closing curtains before sunset save energy?

It may help slow heat loss through windows. The Ideal Home report does not measure energy consumption or confirm a specific saving, so the effect will depend on the home and its window coverings.

When should I close the curtains?

The report recommends closing them shortly before local sunset. The exact time varies by location and date; the writer used a reminder about 20 minutes before sunset in one example.

Which curtains or blinds worked best in the reported test?

In the writer’s home, thermal curtains and blinds had the largest reported temperature difference, at 2°C. Wooden blinds showed just under 1°C, while standard curtains showed about half a degree. These were individual readings, not universal results.

Can I calculate how much money this will save?

Not from the report. It gives no estimate of reduced heating use or bill savings. Any financial effect would depend on the home, weather, heating system, energy prices and how much heat the coverings retain.

Source: rss