Martin Lewis's 4pm curtain rule: a simple, cost-free way to keep your home warm this winter

As the nights draw in and energy bills continue to bite, Martin Lewis has revived a piece of advice that costs nothing and could keep your home warmer for less. The founder of MoneySavingExpert suggests a simple routine change at around 4pm: close your curtains as dusk falls. It is a tip that many may think they know, but Lewis insists that doing it rigorously can make a real difference to your heating bills.

With the clocks about to go back and temperatures dropping, households across Britain are looking for ways to stay cosy without sending their energy costs soaring. Lewis, who appears regularly on ITV and the BBC, has long championed practical, no-nonsense savings. His curtain advice, first shared in November 2022, has been verified by his team as still relevant for this winter.

Why drawing your curtains at 4pm makes sense

As the days shorten, the sun sets earlier. On November 15, for example, sunset is around 4.14pm, and by the end of the month it falls to roughly 3.55pm. Once the sun goes down, your windows no longer let in natural warmth. In fact, they become a source of heat loss.

Closing your curtains as evening approaches creates an extra barrier between the warm air inside your home and the cold glass. Warm air moves by convection: it rises, cools against the window, and sinks, drawing more warm air towards the pane. Curtains interrupt this cycle, helping to keep the heat where you want it.

Lewis recommends keeping curtains open while daylight lasts, then drawing them shut as darkness falls. He told viewers: “Use tactical curtains. When the sun is shining, it is letting light and heat into the house, so you want the curtains open. When it gets dark, it's not, so you want to keep the heat in by closing the curtains. I know we all know that, but doing it rigorously can help insulate, especially if you line it with a fleece.”

No need for expensive thermal curtains

You do not need to spend money on fancy thermal linings. Lewis has suggested a budget-friendly alternative: line your existing curtains with a cheap fleece blanket. This mimics the insulating layers of winter clothing, trapping air and reducing heat loss. He points out that there are plenty of online tutorials showing how to do this at home, but stresses that any fabric used must be fire-resistant.

For those who can stretch their budget, thicker or thermal-lined curtains are another option. But the 4pm rule itself costs nothing and can be adopted immediately.

Other energy-saving tips from Martin Lewis

The curtain trick is just one of many energy-saving measures Lewis promotes. He also recommends fitting reflective panels behind radiators to bounce heat back into rooms, and sealing draughts around windows and doors.

His broader philosophy is to “heat the human, not the home”. This means using targeted measures to stay warm rather than heating the whole house when you are only using a couple of rooms. Wearing extra layers, using blankets, or heating only the room you are in can help households avoid wasting energy on empty spaces.

With colder weather approaching and family budgets under strain, small changes to how and when you use energy may help keep some of that expensive warmth inside your home. It is the kind of pragmatic, common-sense advice that has made Lewis a trusted figure in British households.

What readers suggest: practical tips from the public

Sharing their own advice on Reddit's Life Hacks forum, one user suggested using clear packing tape to tackle draughty windows. They wrote: “If you have a draft coming from an old double hung or sliding window, simply take some clear packing tape and try to cover up the gaps that make it drafty. It's not going to completely keep the cold out, but it will certainly slow it down considerably. Did this a few times to some apartment windows where the landlord was too cheap to fix the windows and you could feel the room warm up almost immediately.”

Another commenter advised heating only the most insulated rooms: “If your home doesn't have central heating, you can heat only the most insulated rooms where people spend most of their time. The first month in my house, I heated every room and spent 4x the energy I've been using since. Invest in a couple pairs of thermal hiking socks. If you're sitting at the computer, stand up and bounce every once in a while to keep the blood flowing in your legs and feet.”

A third contributor pointed out that electric ovens are not vented, so the heat from cooking radiates into the room. They suggested leaving the oven door open after use to make the most of that warmth.

Frequently asked questions about Martin Lewis's 4pm curtain rule

Does closing curtains at 4pm really save energy?

Yes. Closing curtains as dusk falls prevents warm air from escaping through windows. This reduces heat loss and can lower the amount of energy needed to keep your home warm, potentially delaying the moment you need to switch on the heating.

Do I need special thermal curtains for this to work?

No. Standard curtains can be effective, especially if you line them with a fleece blanket or other insulating fabric. The key is to close them before the temperature drops and to ensure they fit snugly against the window.

Is the 4pm rule suitable for all homes?

Yes, it works in most homes, though the exact timing may vary depending on where you live and the time of sunset. The principle is simple: keep curtains open when the sun is shining, close them when it gets dark.

What other low-cost measures can I take to cut heating bills?

In addition to the curtain rule, you can fit reflective radiator panels, seal draughts, wear extra layers, and heat only the rooms you are using. These small changes can add up to significant savings over the winter months.