Engineered Durability; Completion of a 10-year Project Robert Leicester* Chi-Hsiang Wang* Minh Nguyen* Greg Foliente* Laurie Cookson* *Research Scientist CSIRO Melbourne, Australia Ivan Cole Deputy Chief (Science) CMSE, CSIRO Melbourne, Australia Colin Mackenzie Technical Manager Timber Queensland Brisbane, Australia Summary A 10 year national project in Australia to develop durability models for timber construction has recently been completed. The models predict the attack of timber by decay fungi, subterranean termites and marine borers and also the corrosion of metal fasteners. They are applicable to all timbers species and all locations in Australia. 1. Motivation The development of structural timber engineering during the past few decades has brought the technology to be well positioned for compliance with performance based criteria. However the Achilles heel of this technology has been the failure to include useful models for the effects of durability. Performance requirements are stated terms of a failure within a given service life. This is stated in the draft ISO standard ‘General Principles on the Design of Structures for Durability’ [1]. The Australian Building Codes Board guidelines document ‘Durability in Buildings’ [2] and some Australian Standards such as AS 4678 ‘Earth Retaining Structures’ [3] specify a design life according to the building component or end use. So durability models are essential tools for complying with performance requirements.