Choosing a thermal curtain – fabric, sizes & hanging
A good thermal curtain is more than thick fabric: build, length and hanging decide whether it noticeably softens draughts and cold glass.
What makes a thermal curtain
Typically a densely woven fabric with a lining or coating on the back. Several layers hold still air between the room and the pane. Many models also darken the room. Look at the maker's information on build and care, not at promises in numbers.
Choosing fabric and hanging
Eyelets or pleat tape give neat folds and close better at the top than loose loops. Pick a colour that suits the room and check that the fabric is washable. A sturdy rod must carry the extra weight of a lined curtain.
Sizes as a guide
Width: window width × 1.5 to 2. Rod: roughly 10 to 20 cm above the frame and extending 15 to 20 cm at each side so the curtain covers the window fully. Length: to just above the floor or to the sill. In front of radiators go shorter so heat reaches the room.
Combine and use day to day
Close in the evening, open by day when the sun shines. Seal strips on gaps or insulation film improve the effect all round. In a rental: tension rod or adhesive holders instead of drilling; check your lease. Keep ventilating so moisture does not build up behind the curtain.
Checklist before buying
- Window width measured, factor 1.5–2 planned
- Rod carries the weight and extends at the sides
- Length suits floor or radiator
- Hanging style chosen (eyelets/pleat tape)
- Lease checked: tension or adhesive solution