Why having window insulation is important

Double glazing and curtains operate in the same way; by creating still air spaces that act like insulation. Double glazing is now required under the New Zealand Building Code for new homes and in many cases costs no more than single glazing to install. It can still be reasonably expensive to retrofit to existing homes, so we offer it as an alternative to good curtains to show better window performance in HomeFit, and if you have both you are more likely to get HomeFit PLUS.