Building for the Future: Designing for tomorrow’s climate instead of yesterday’s

October 22, 2026

Evaluating a new approach to developing average and extreme future weather files for residential building simulation in Australia.

Homes built today are expected to be in use well into the 2070s, yet most Australian building assessments still rely on weather files based on historical observations. This report presents the Hub’s co-designed method for generating future Typical Meteorological Year (TMY) and eXtreme Meteorological Year (XMY) weather files for residential building simulation. The prototype files cover eleven locations and use high-resolution regional projections from seven global climate models, two emissions pathways and three future periods (2030s, 2050s and 2070s). They were formatted for NatHERS-accredited software and tested by building designers and assessors using HERO, FirstRate5 and AccuRate.

Testing confirmed the files are technically fit for purpose. Future TMY files show increasing cooling demand across all locations, while XMY files add a new heatwave stress-testing capability not possible with current NatHERS files. Results varied substantially between climate models, with Sydney’s cooling loads differing by up to 259% under the same emissions scenario, so practical guidance on file selection and interpretation is essential. The report also outlines limitations and future work, and calls for a long-term national capability to maintain and support future weather files.