Home Q&A: How to use curtains to banish draughts

Curtains are not just an old-fashioned fix. Here's what they can do if windows with higher U-values in older double glazing are not delivering

Fri, 08 Aug, 2025 - 16:50

Kya deLongchamps

Curtains are an old-fashioned fix for draughty windows, and with highly insulated windows, are only needed for aesthetic flair and privacy. That said, here’s what they can do if your windows with higher U-values in older double glazing and rattling frames are not delivering.

Curtain lining can provide an additional thermal and even acoustic barrier to improve the U-values of your curtains and windows. Alternatively, you could deploy two sets of curtains, with insulated lined curtains for cooler conditions and light to medium varieties for spring/summer. Look for specific thermal interlining when purchasing.

For PVC windows and French doors, look into what’s termed “perfect fit” insulated blinds. These highly affordable blinds are comprised of a fabric pleated surface set in a custom frame with a honeycomb structure that holds off cold and keeps a modest amount of heat indoors. Pull them up or down out of the way on sunnier days to let in some free, passive UV gain. Suppliers include Blinds2go.ie.

For large picture or period windows, take the curtains as close to the ceiling as possible in pencil pleats and let them pool slightly on the ground.

Natural Cosy Texture door curtain, from €76, Next.

Ensure the curtain is hung well beyond the reveal (8cm wouldn’t be excessive). All curtains should be at least twice their size in centimetres to the size of the window to allow for draping. Velcro strips to hold it to the wall, in combination with a blind, can add to the curtain’s thermal talents.

Don’t forget ropy old doors. These can also take a curtain detailed with internal wadding, but this must be pulled completely and safely back when not in use. Thermal door liners or even rugs can be pinned up on a door to cover gaps between boards, touching the floor to exclude some draughts. Temu offer magnetic, no-drill door curtains from around €18, Temu.com.