weatherization piechart 2Insulation acts as a barrier to heat loss and heat gain, particularly in roofs and ceilings, walls and floors. It helps to keep your home warm in winter and cool in summer.

Why is insulation important?

Half of the energy we use to heat or cool our homes can simply leak out without insulation.

insulationInsulation helps to:

  • reduce use of heating and cooling systems
  • save money on your energy bills
  • improve your comfort at home.

Some types of insulation can also make your home more soundproof.

Insulation requirements

Whenbuilding or renovating talk to your builder, insulation expert or local council about requirements. Going above the minimum standards will result in greater comfort and energy savings.

Types of insulation

There are two main types of insulation:

  • Bulk insulation (usually batts, rolls or boards) acts as a barrier to heat flow, keeping unwanted heat in or out of your home. It can be made from materials like glass wool, polyester, wool or recycled paper.
  • Reflective insulation helps keep your home cool in summer by deflecting radiant heat. It’s usually shiny aluminium foil laminated onto paper or plastic and is available as sheets and batts.

Some insulation products are available that combine features of both bulk and reflective insulation.

What type of insulation is best for you will depend on where you live and whether you need to keep heat in, or out, or both. Your home’s design, the material it’s made from and its orientation to north are also factors.

The Your Home Technical Manual has detailed information about climate zonesorientation and insulation types.


Insulation’s ability to resist heat flow (prevent heat leaking in or out) is described as its ‘R-value’. The higher the R-value, the better it insulates. Insulation products with the same R-value will provide the same level of insulation if installed correctly.

The level of insulation needed will depend on your home and climate zone.

The Your Home Technical Manual has information about recommended insulation levels for your climate.

When to insulate

The best time to install insulation is when you are building or renovating your home. Insulation should be combined with good house design so it can do its job properly.

If you’re going to insulate your home at another time, the effectiveness and cost will depend on how easy it is to install. For example, it may be more difficult to install insulation in existing walls.

What to insulate

Ceiling insulation is particularly important, but there are other areas of your home that can be insulated as well. To maximise the efficiency of your insulation, draught-proof your home to reduce the leaking of heated or cooled air.

Roofs and ceilings

If your roof or ceiling isn’t insulated, you could lose up to 45 per cent of your heating and cooling energy via the roof. Verandah roofs should be insulated in hot climates to reduce heat from the sun, as this not only affects the space below, but also the temperature inside the house. Covered verandahs and garages might benefit from insulation if you spend a lot of time in these areas, especially if you are heating or cooling them.


Uninsulated walls can increase heat loss in winter by 15 per cent.


Heat can be lost through some types of floors – up to 5 per cent of your winter heat. Carpets are one option to insulate a floor. In hot climates floor insulation may interfere with the natural cooling from the ground beneath the house.

Water pipes

Water pipes inside walls can also be insulated when building or renovating.

Why Insulate Your House?

Heating and cooling account for 50 to 70% of the energy used in the average American home. Inadequate insulation and air leakage are leading causes of energy waste in most homes. Insulation:

  • saves money and our nation’s limited energy resources
  • makes your house more comfortable by helping to maintain a uniform temperature throughout the house, and