David on making the most of curtains

Effective curtains can reduce heat loss by 60 percent for single glazed windows, and by as much as 50 percent for double-glazing.  The good news is that there are a few, simple low-cost modifications you can make to improve the performance of your existing curtains.

Ideally, best-performing curtains are double layered (two layers of fabric) with thick lining, measured to reach the floor and fitted tightly against the window frame. The aim is to stop the ‘reverse chimney effect’: At night, cold air between the curtain and window sinks to the floor between gaps under the curtain. 

The resulting temperature differential draws precious warm air from your living space through gaps around the top and sides of the curtain.  The window then cools much of this warm air.

This is why we recommend curtains to reach the floor.  If your existing set doesn’t, consider these tips:

• Quick fix: block gaps at the top. Where brackets are used to suspend the curtain track forward of the window frame, fix a thin length of timber above the brackets – or even a rolled up towel or bed sheet will work perfectly.  This will block gaps in the same way pelmets used to.

• DIY enthusiasts: replace the brackets with face-fixed tracks, screwed directly into the window frame. Note that eyelet curtains on rod tracks are especially draughty but are not easily converted to face-fixed tracks.

• Reduce gaps along the window sill: try placing a temporary item – not a bed – against the base of the curtain at night to press closed any gaps. Beds should ideally be positioned nearer warmer internal walls away from windows if space permits.

• Small Velcro pads placed at intervals will secure the curtain to the window frame if you want an unconventional yet very effective solution.

• If tucking curtain bottoms into the window sill itself, you want to avoid condensation soaking into your curtains, which then encourages mould.

Remember to open curtains fully during the day for maximum free solar heat gain.  This especially includes net curtains if you don’t mind reduced privacy.

If you want to get your curtains lined, the Wellington Curtain Bank offers a paid service for detachable lining – all you need to provide is your curtain measurements and we can assist.  The Curtain Bank also supplies free curtains to Community Service Card holders in the Wellington Region.  To donate or receive curtains, please contact: (04) 385 0500 ext 705.