For designers, a key consideration to improve the environmental performance of new products and services is energy and resource efficiency (eco-efficiency). This is particularly important for household energy using products (EuPs) as they consume significant energy during the consumption (use) phase of their lifecycle. EuPs incorporate many types of consumer electrical and electronic products, including televisions and computers as well as the many other powered kitchen, laundry, bathroom and personal electronic devices of which ownership, both individually and cumulatively has increased dramatically in modern households. A consequence of EuP ownership and changing behavioural patterns is that EuPs cumulative contribution to overall household energy use is increasing in Australia, at 4.7% per annum. This is despite the sustained efforts over many years to improve energy efficiency of individual EuPs that is claimed to have improved at a rate of 2% per annum since 1970. This begs exploration of the drivers underpinning this divergence between predicted energy conservation through efficiency and actual energy use. The aim of this study is to investigate why household energy use from EuPs continues to rise. Such situations are described as ‘rebound effects’ where ‘designed in’ energy savings are not achieved. Exploring the proposition of the rebound effect, this study investigates design, ownership and use parameters of televisions (and peripheral equipment), washing machines, dishwashers and refrigerators benchmarked over a period of time. Drawing upon a variety of technical and behavioural criteria, data is mapped and presented for analysis to locate, identify and remark upon the qualities and significance of a likely rebound effect. Such information, where identified, highlights the hidden implications and significance of product use and user behaviour in shaping the success, or otherwise, of design strategies to conserve energy and consumption.