How much insulation do I need?

How much insulation do I need?

This will depend on which climate zone you live in. In each climate zone, the Building Code of Australia has determined a minimum amount of needed insulation expressed in R-value (the efficiency of a material at stopping heat flow through it.)

This is the Building Code’s recommended amount of insulation, in R-values, for each climate zone and insulation type:

Climate Zone

1

2

3

4

5

6

7

8

Ceiling insulation for homes with very light coloured roofs

R4.1

R4.1

R4.1

R4.1

R4.1

R4.1

R4.1

R6.3

Ceiling insulation for homes with light coloured roofs

R4.6

R4.6

R4.6

R4.6

R4.6

R4.6

R4.6

R6.3

Ceiling insulation for homes with dark coloured roofs

R5.1

R5.1

R5.1

R5.1

R5.1

R5.1

R5.1

R6.3

Wall insulation

R2.8

R2.8

R2.8

R2.8

R2.8

R2.8

R2.8

R3.8

Underfloor insulation

R1.5

R1.0

R2.25

R1.0

R2.25

R2.25

R2.75

R3.25

R4.1 is about 20 cm thick (depending on the material and the density).

You will also need to work out the area of the space you are insulating in square metres. 


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