Winter curtains: keeping the heat at home

Season · Winter 2026-2027

In winter a window does not only let cold through its glass: it lets cold through its sides. A dense curtain acts on both, and it acts on the heat already in the room, which is why it goes up before the deep cold rather than during it.

Made-to-measure thermal curtain at a window in winter

What cold costs a window

According to ADEME, windows account for 10 to 15% of a home's heat loss. The Union des Fabricants de Menuiseries notes that this estimate is low, because it does not account for air leakage around windows already installed.

It is precisely that circulating air a dense curtain stops, and that is what double glazing alone does not fix. The condition is simple: the panel must overlap the frame, not stop at the glass.

Which curtain for winter

The useful criterion is fabric weight. Everything else, colour included, comes after.

Beige thermal and acoustic blackout curtain

3-in-1

Thermal acoustic blackout curtain

620 gsm · 7 °C · 22 dB

Three dense layers, 100% blackout. This is the winter one: it insulates, blocks light and attenuates noise on the same panel.

Single-layer blackout curtain

310 gsm · total blackout, reversible

Complete darkness without the weight. It blocks light, but does nothing thermal or acoustic.

Beige linen-look light-filtering curtain

Light-filtering curtain, linen look

265 gsm · filters 70% of the light

To keep some daylight when it grows scarce. To layer with a thermal blackout for the night.

Where the cold is felt most

Four places come back every winter, and each is treated differently.

The bedroom at first light

The glazed surface cools the air all night. It is the room where the 7 °C difference at the glass is felt most.

The front door

Cold comes in at the bottom and along the sides. The door curtain is fitted differently from a window curtain.

The conservatory

A lot of glazing, little thermal mass. It is the one space where cold is a recognised problem before it becomes a bill problem.

The roller shutter box

A thermal bridge the curtain does not always cover. The fitting is planned in advance.

The winter file

Twenty articles to choose, fit and check. They answer questions in the order they come up.

Cold conservatory in winter: heat or insulate A curtain in front of a radiator Baby's room in winter: the right temperature Where the draught at the window comes from Tenants: insulating without building work Insulating your windows from the cold without building work How to choose a thermal curtain Thermal curtains: what the reviews say How an anti-cold thermal curtain works What a thermal curtain changes on the bill The best thermal curtains compared Which way round to hang a thermal curtain Does a double curtain insulate better Heavy or light curtain, which insulates The thermal curtain for a front door Thermal curtain or double glazing Thermal curtain or secondary glazing Thermal curtain or roller shutter Thermal blackout or plain blackout Choosing a thermal blackout

Frequently asked questions

Does a thermal curtain replace double glazing?

No, and it is not a substitute. It acts on a share the glazing does not address, the air circulating around the panel, and it needs no building work. The detail is in thermal curtain or double glazing.

Should curtains stay closed during the day in winter?

No, not on a sunlit window: the day's solar gain is free heat. The good habit is to open wide by day and close before dusk, not at bedtime.

What thickness really insulates?

Below 300 gsm the effect stays marginal. Our main range is 620 gsm across three layers, which gives up to 7 °C difference at the glass. The full reasoning is in which weight to choose.

Does a made-to-measure curtain insulate better than a standard one?

Yes, and it is not a question of fabric. A standard curtain leaves gaps along the sides and at the top: air passes through them, and part of the fabric's performance is wasted.

When should they be fitted?

Before the first deep cold, generally in mid-October. The curtain limits what is left to lose; it does not recover what has already been lost. For the period before, see autumn curtains, and for the late-November operation, Black Friday 2026.