Everyone working on the ground with whānau and their homes has long agreed that curtains are important. Their experience told them that curtains made a difference to how comfortable a room was.
The problem was that the science hadn’t caught up. There was no evidence to back up their experience.
Now BRANZ researchers have started building that evidence in a project with Beacon, the Home Performance Advisor training programme and Sustainability Options.
What we learned
Having a curtain is better than having no curtain at all – bare windows are cold to sit near, and they let warmth out and cold in.
Long curtains, ideally to the floor, are better than short curtains – the cold air near the window falls out the bottom of short curtains, pulling the heated air in at the top (where the heat is lost through the window) and making the wall below the curtain cold.
Tracks that are tight to the wall are better than tracks with gaps at the top – tight tracks stop heated air being drawn down and help hold the cold air there.
Curtains with thicker linings keep more heat inside and stop cold air entering the room.
The science explained
This brochure explains the science behind how curtains work and gives some suggestion about how to improve your curtains.