Step 2. Determine the minimum R-Value of insulation needed to meet BCA deemed-to-satisfy requirements in your climate zone.
The values in this table can also be used as a guide when installing insulation into alterations and additions, or retrofitting existing homes with no insulation.
It should be noted that these are minimum values only, and that upgrading your insulation to a higher material R-Value can provide a better level of the resistance to heat in your home. Understanding the difference between R-Values is important as it can mean the difference between getting an average product for your home with average benefits, and getting the best product for your home.
Don't know what climate zone you are? Check out Step 1.
Minimum R-Value Of Insulation Needed To Meet BCA Deemed-To-Satisfy Requirements
Note that your climate zone is affected by your elevation above sea level (above or below 300m). Please click here to check your elevation in order to choose the right insulation to comply with the BCA.
| Climate Zone |
Zone 1 & 2 (<300m) |
Zone 2 (>300m), 3, 4, 5, 6, 7 |
Zone 8 |
Dark coloured roof tiles or metal roof (solar absorptance > 0.6)
and no sarking |
R5.0 |
R5.0 |
R6.0 |
Dark coloured roof tiles (solar absorptance > 0.6)
with Enviroseal Roof Tile sarking, with VENTS |
R3.5 |
R5.0 |
R6.0 |
Light coloured roof tiles or metal roof (solar absorptance between 0.4 – 0.6)
and no sarking |
R5.0 |
R4.1 |
R6.0 |
Light coloured roof tiles (solar absorptance between 0.4 – 0.6)
with Enviroseal Roof Tile sarking, with VENTS |
R3.0 |
R4.1 |
R6.0 |
Dark coloured metal roof (solar absorptance > 0.6)
with ResiWrap sarking, with VENTS |
R3.5 |
R4.1 |
R6.0 |
Dark coloured metal roof (solar absorptance > 0.6)
with Anticon 55, without VENTS |
R3.0 |
R3.0 |
R4.1 |
Light coloured metal roof (solar absorptance between 0.4 – 0.6)
with ResiWrap sarking, with or without VENTS |
R3.5 |
R4.1 |
R6.0 |
Light or off white/cream coloured metal roof (solar absorptance ≤ 0.4)
with Anticon 55, without VENTS |
R2.0 |
R2.0 |
R4.1 |
Off white/cream coloured metal roof (solar absorptance ≤ 0.4)
and no sarking |
R4.1 |
R3.5 |
R6.0 |
Off white/ cream coloured metal roof (solar absorptance ≤ 0.4)
with ResiWrap sarking, with or without VENTS |
R3.0 |
R3.5 |
R6.0 |
*If metal framing is used, a thermal break tape must be used over the Enviroseal fabric.
**Contact Bradford for a solution.
Note that the use of high levels of insulation to meet energy efficiency and comfort requirements can lead to an increased incidence of condensation in walls and attic spaces in cold climates. This is because of the insulation’s effectiveness at keeping the warmth within the home but vapour’s ability to pass through plasterboard and standard insulation. To address potential condensation problems Bradford recommends the installation of Anticon roofing blanket under metal roofs where the ceiling is insulated. The inclusion of building membranes with a high permeability, such as Enviroseal, and the inclusions of roof ventilators will also help minimise the incidence of condensation. Contact Bradford Technical personnel for detailed information.
