Ever since energy efficiency provisions were introduced into the National Construction Code in 2003, there have been increased requirements for energy-efficient measures with each iteration of the code, particularly around insulation. This is based on the often-repeated objective of reducing Australia's greenhouse gas emissions in the light of climate change. However, what has been conspicuously lacking is undisputed evidence whether the code has been achieving its stated objectives, whether the standards around energy-efficient construction and product testing have been fit for purpose, and whether these will continue to be suited to a changing climate. In fact, there is evidence that the intended and achieved goals are substantially different. This paper is a critical essay, set in the context of the Australian Building Codes Board's scoping study into "Energy efficient measures for 2022 and beyond", and makes the case that current insulation requirements are already excessive against considerations that should be made, as a higher priority, for fire safety, thermal bridging, condensation, heat stress resilience and thermal comfort.