When it comes to calculating the thermal performance of building systems, recent changes in regulations have made things a bit more complex. The shift from NCC 2016 Section J to NCC 2019 Section J brought about significant changes in the calculation methodology. The updated guidelines now require thermal bridging, which refers to the loss of insulation caused by interruption due to framing, to be taken into account.
Let's take a lightweight clad wall system featuring a 92mm steel stud frame installed at 600mm intervals as an example. Under the previous NCC 2016 Section J, if we were to install a 90mm R2.5 Gold Wall Batt insulation product in this system, it would yield a system thermal performance rating of approximately R2.6.
However, under the new NCC 2019 Section J guidelines, the same system would have a significantly lower system thermal performance rating of around R0.85. As you can see, the change in the calculation methodology has led to vastly different results for the same system.
To simplify this process and help you comply with NCC 2019 Section J, we've developed the CSR Thermal Calculator. This user-friendly tool takes the complexity out of determining system thermal performance values. It provides a straightforward interface where you can select the elements of your system and input some basic information about the framing. The CSR Thermal Calculator takes care of the rest and delivers a calculation result based on the inputs you provide, all following the methodology outlined in Australian Standard AS 4859 Part 2.
In its initial release, the CSR Thermal Calculator includes 18 commonly used roof, wall, and floor systems for thermal calculations. As design requirements evolve, we will continue to add more systems to the calculator over time.
With the CSR Thermal Calculator, you now have a quick and easy solution to perform thermal calculations that align with NCC 2019 Section J requirements.