This chapter provides a review and critique of the development and current status of approaches to improve energy efficiency and broader sustainability in the Australian built environment. The focus is on the minimum building performance requirements set through the National Construction Code—Building Code of Australia, but the chapter also includes other mandatory and voluntary approaches which have been introduced over the past two decades. The chapter concludes with a discussion that highlights current gaps that relate to the delivery of a low-carbon/low-energy built environment. It recognises that Australia currently fails to meet international building performance best practice standards, particularly in the residential sector, and this situation can only be reversed if various levels of government in Australia increase the regulated level of energy performance of buildings coupled with a more holistic and progressive inclusion of all energy consumed and generated within a building. This would be better aligned with improving actual impacts a building has over its lifecycle and on the community at large.