Drivers of damage resulting in the inability to live in or operate out of domestic and commercial property can be due to the combination of the elements during severe weather impacts that are not accounted for in Australian building codes and standards governing the design of our homes and businesses.

For example, analysis of building damage coupled with insurance claims data, has highlighted issues with wind and rain on the performance of contemporary engineered structures (ranging from homes through to commercial and public buildings).  Significant losses in terms of cost of repair or rebuilding, and loss of income through building not being able to function has been documented following severe Tropical Cyclones Yasi, Marcia, Olwyn and Debbie [1].

Insurance claims were examined to derive costs of damage resulting from wind-driven rain water ingress entering buildings through flashings, doors and windows, even when there was no damage to the building envelope. Approximately 70% of Strata claims reviewed had some form of damage from water ingress.  Of the detailed strata claims reviewed, the percentage of claim costs associated with the water ingress damage varied from 2% to 60%.  For the housing claims reviewed, the average cost of repairing damage from the water ingress was $25,000.

Current Australian regulations for windows for rain resistance have minimal requirements. Better understanding (quantification) of the wind gusts with rain intensity coupled with the building envelope’s “porosity” is required to design and test cost effective solutions.  Similarly, drivers of loss from severe hail storms occur with wind and rain.  Again, to improve building performance, data on multiple aspects of the event is required; e.g. hail size/rate, coupled with wind velocity and rainfall.

The presentation is to highlight important weather climate research aspects for building code development.