Exemplary Energy has begun collaborating with Dr Tim Law, an expert architectural scientist specialising in mould in Australian buildings. Dr Law is Head of Building Sciences at the Melbourne-based consultancy, RIC Solutions, and was previously a part of the University of Tasmania’s Tasmanian Architectural Science Laboratory (TASL).
Currently, RIC Solutions is researching compliance paths for the condensation and mould provisions in the National Construction Code (NCC) including how they relate to the AIRAH guide DA07 ‘Criteria for Moisture Control Design Analysis’ proposing Moisture Design Reference Years (MDRYs) and Moisture Reference Years (MRYs) along with the alternative of 10 or more consecutive years of weather data which include hourly precipitation data.
For now, our collaborative work is focused on three radically different sites: Brisbane, Darwin and Melbourne. For each place, a 15-year weather file has been prepared along with the MRY derived from that data for testing and analysis. RIC Solutions has been provided with this data along with the identification of the 10th and 90th percentile years according to the 3 alternative definitions of temperature. They will use that data in hygrothermal simulations and report on the sensitivity of the results to the definition of temperature selected.
On Monday 13 October, AIRAH’s STG on Building Physics spontaneously convened a virtual meeting for an update on weather and climate data available for hygrothermal simulations. Exemplary Energy’s Trevor Lee and Hong Gic Oh attended to advise the STG of the current status of our analyses. RIC Solutions’ Dr Tim Law was unavailable due to an unfortunate clash with the Building and Plumbing Commission industry conference in Melbourne.
On Monday, 3 November, Exemplary Energy conducted a trial to generate MRY files by adapting the Brambilla (2022) method – originally designed to select MRYs on a yearly basis to a monthly selection for Brisbane, Darwin, and Melbourne. The method is using wet index (based on wind-driven rain) and dry index (based on dry bulb temperature, relative humidity and station pressure) to calculate the moisture index. Dr Law is currently performing a sensitivity analysis for Melbourne.
According to AIRAH DA07 (Criteria for moisture control design analysis in buildings), Moisture design reference years: it suggests using MDRY from the 10th-percentile warmest and 10th-percentile coldest years from a 30-year weather analysis. However, there are no measured hourly precipitation data for 30 years in Australia. Accordingly, this would require application of Exemplary’s in-house software for synthesizing (disaggregating) hourly values from daily data in the early years (Oates et al, 2025).
Dr Law mentioned “…Just stuck to 10 consecutive years. That keeps us well within the automatic tipping buckets era without a need to disaggregate rainfall data”. Similarly, Jesse Clarke (Pro Clima) noted “…Using repeated yearly data means the results are periodic in nature, if they are not then there is clearly a simulation problem. This is a massive bonus for fault finding and determining if silly inputs have been used in a relatively immature market of WUFI users. The 10 consecutive years are technically more accurate.”
Work is progressing in this field, including a recent report by RIC Solutions (T Law et al) to the Australian Building Codes Board (ABCB) entitled ‘Condensation: Physical Testing in Tropical and Subtropical Climates’. Its publication is understood to be imminent, but for now, to appreciate its context, see the ABCB’s ‘Handbook of Condensation in Buildings’ here.
The intention is to expand this to the full NatHERS list of climate zone locations for routine practitioner applications.
The report by RICsolutions is now with the ABCB. Given that the NCC has been ‘frozen’ until 2029, it is anticipated that there will be a long wait before the ABCB chooses to make it publicly accessible. Meanwhile, Exemplary and RICsolutions are collaborating with AIRAH’s Building Physics Special Technical Group (STG) to prepare advanced advice for AIRAH members and subscribers to ‘Ecolibrium’.
Updates on this work will be included in future editions of ‘Exemplary Advances’.