Insulation is the most effective way to improve the energy efficiency of a home or a building. Insulation of the building envelope helps keep heat in during the winter and out in summer to improve comfort and save energy. Insulation could add additional benefits such as acoustics and waterproofing. Effective draught proofing, moisture control and ventilation are important at design stage.

The appropriate level of insulation intervention will depend on the energy zone, building construction type, and whether auxiliary heating and/or cooling is used.