The majority of the environmental impact of a product is decided during the design phase, and as such there has been a rapid growth in generation of methodologies and tools that aim to improve design and include sustainability considerations in product development. Although these methodologies and tolls and have introduced measurable benefits, in most cases they have been incremental in nature as opposed to producing radical `Factor X` improvements. The highlights the need for a careful analysis of existing sustainable design methods to identify their shortcomings and to enable a greater understanding of ecodesign and its extension into sustainable design improvement. This paper provides a brief overview of the evolution of ecodesign and its extension into sustainable design. It assesses the key influencing factors of current practice and identifies a number of future research challenges, promoting the next stage in its development in which sustainability will become a ubiquitous part of the design process.