Roofs and ceilings work in conjunction when it comes to insulation.

Install insulation under the roofing material to reduce radiant heat gain.
Install insulation in the ceiling to reduce heat gain and loss. In most cases ceiling insulation is installed between the joists.

Verandah roofs should be insulated in hot climates where outdoor living spaces are used extensively, to reduce radiant heat gain. Heat build up under verandahs not only affects the space below but can affect conditions inside the house.

Bulkheads (wall sections between ceilings of different heights) must be insulated to the ame level as the ceiling, as they are subjected to the same temperature extremes.

Save up to 45 per cent on heating and cooling energy with roof and ceiling insulation.

External walls should be insulated to reduce radiant, conducted and convected heat transfer. Wall insulation can be installed:

Within cavities
Within stud frames
On the outside of stud frames
On the inside or outside of solid walls

Depending on the particular situation, some forms of insulation can double as a vapour or moisture barrier.

Save up to an additional 20 per cent of heating and cooling energy with wall insulation.

Floors require insulation in cool climates and often in other climates. Regulation does not require insulation under ground concrete slabs when ground water is present.

Insulate the underside of suspended floors:

In cool temperate and alpine climates
In temperate climates in some cases
In high humid and hot dry climates where air conditioning is used.

Insulate the edge of ground slabs:

In cool temperate and alpine climates.
In temperate climates where slab heating is used.

Insulate the underside of ground slabs:

In alpine climates
Where groundwater is present

Enclosing sub-floor spaces in mixed climates may be sufficient to reduce heat loss.

Save up to 5 per cent on winter energy costs with appropriate floor insulation.