This is a follow up from our previous article in our June edition Vulnerability of National Construction Code (NCC) changes for 2025.
Formal public comment closed on Monday 1 July 2024, we commented to the Australian Building Codes Board (ABCB) on Condensation section (Condensataion mitigation measures) and Section J (Commercial energy efficiency provisions) to improve the NCC changes for 2025 .
We pointed out that the condensation analysis didn’t use the weather and climate data compiled directly from the records of the Bureau of Meteorology to include coincident hourly precipitation data (mostly rainfall) in the simulations of building component performance. We cited our extended abstractt: Tarquini, Lee and Ferrari “Improving Australian Weather and Climate Date Services” in Proceedings of the 2022 Asia Pacific Solar Research Conference) as a reference.
And, more importantly, we highlighted how the J1V3 proposal is based on “CSIRO Projected Weather Files” (actually climate files) for building energy modelling, all of which have multiple time off set errors making the simulation results in the Consultation Regulation Impact Statement (CRIS) potentially misleading and counterproductive. Worse still, the ABCB proposes this data as mandatory for simulations to verify compliance with the changed NCC 2025.
We highlighted that we addressed this time off set errors twice from two years ago and offered our articles (CSIRO timing offset error in several weather elements – Exemplary Energy Blog and Solar data timing error skews simulation results – Exemplary Energy Blog) and paper (Tarquini, Lee and Ferrari (2022). “Quality Assurance of Available Meteorological Data” in Proceedings of the 2022 Asia Pacific Solar Research Conference ) as a reference.
We look forward to seeing this feedback is adopted so NCC can perform more precise analysis for its proposed 2025 changes.
Update 2024-07-11: Just before close of business, CSIRO has circulated a statement of correction, with their climate files being “updated” to correct the errors that they have known about, and we have been urging them to fix, for 26 months. No statement has been made about how the erroneous data may have skewed the CRIS for the proposed changes to the NCC. Also, we have not checked that their “updated” files are now fit for purpose.