Installing insulation in buildings not only provides comfort but also shuts out noise. Issues Insulation reduces the heat flow through walls and ceilings by up to 90 per cent. Australian Standard 2627 lists recommended cost-effective insulation values for locations throughout Australia. These call for, at a minimum, reflective foil insulation in the walls and foil plus 50 mm blanket in the roof in mild climates, and at least R1.5 batts in walls and R3 bulk insulation in ceilings in colder climates. Installation of reflective foil is recommended in sunny areas or climates with cold, clear nights, as it improves comfort and acts as a vapour barrier.
Reflective foil requires an airspace next to the shiny surface to act as an insulator.
Ensure that foil is not sandwiched between the ceiling lining and the roofing, as this negates its insulating properties. In hot humid climates or cold climates, a vapour barrier will minimise the risk of condensation in the insulation and possible damage to the building structure. Shading roofs and walls reduces heat gain. Trees, verandahs and pergolas can also be attractive. Action Limit heat flows through windows Issues Heat is lost through single-glazed windows ten times faster than through insulated walls.