Building for the Future – considering future weather and extremes in assessing building energy efficiency

Ramona Dalla Pozza^1,2, David Hoffmann^1,3,Surendra Rauniyar^1,3, Zhengen Ren⁴, Doerte Jakob³, ,Anthony Wright⁴,Michael Ambrose⁴, Anir Upadhyay⁵, Daniel Daly⁶, William Tolis⁶, Tim Le Mesurier⁶, Hannah Bubb⁶, Erica Kenna⁷

• ¹ National Environmental Science Program Climate Systems Hub
• ² University of Tasmania
• ³ Bureau of Meteorology (Melbourne, Australia)
• ⁴ CSIRO Energy
• ⁵ University of New South Wales
• ⁶ Department of Climate Change Energy and the Environment (Australia)
• ⁷ Australian Building Codes Board

Current building energy efficiency modelling for approval of new buildings is assessed using a sample of actual weather data from the past. However, as our climate is changing, and as buildings designed today have an expected life-span of approximately 50 years, building designs need to consider the future climate. Previous attempts at integrating future climate projections for residential buildings (see link Predictive weather files for building energy modelling – Australian Housing Data (csiro.au) have received critical feedback from across industry and the climate science community as they only capture average future temperatures (not extremes).

The NESP Climate Systems Hub is bringing together climate scientists from the Bureau of Meteorology and the Australian Climate Service, with CSIRO Energy, University of New South Wales, and the residential and commercial building areas within the Energy and Performance Security Division of the Australian government, along with members of the Australian Building Codes Board (ABCB) to explore new approaches to incorporate future climate projections into building energy simulations and building performance assessments.

To provide a meaningful representation of the weather we can expect in the future, this project will develop a dataset-agnostic methodology for generating location-specific future weather files for Typical Meteorological Year (TMY), and three Extreme Meteorological Year (XMY) files representing the most intense, the most severe, and the longest heatwaves using outputs from regional climate models.

This project will produce ‘prototype’ future climate weather files for 12 locations across Australia. These ‘prototype’ files will be tested by building simulation modellers to ensure they are fit-for-purpose. Through co-design with policy and industry experts, this project aims to contribute to improved policy outcomes for NatHERS (Nationwide House Energy Rating Scheme) and NABERS (National Australian Built Environment Rating Scheme), hoping to influence the 2028 update to the National Construction Code for residential buildings.

We would like to acknowledge funding and in-kind support through Australian Government NESP Climate Systems Hub and partners, CSIRO Energy, the ABCB and the National Partnership for Climate Projections (NPCP).