ABSTRACT
Worldwide, sustainable new housing is driven by legislation, with building codes and regulations requiring the incorporation of minimum energy standards. These are enforceable by law and can be upgraded over the years – for example, in the UK, all new housing must be ‘carbon neutral’ after 2016. For the existing housing stock, a different set of mechanisms is required to upgrade sustainability, and there is a need to exploit every opportunity and to provide encouragement in a variety of ways.
