Buildings change in response to various social processes and emerge through the different practices and understandings of people who use, inhabit and work on them. Over time structures acquire a range of meanings as authentic embodiments of the past, including values attached to original fabric, period features, and the patina of worn and weathered materials. Such understandings are associated with cultural, social and economic values that lend support to the importance of conserving and caring for old buildings. However these ideas have the potential to conflict with an increasing emphasis on energy-efficient renovation, entailing a radical transformation of the built environment in response to fears about climate change. Concretely, a range of measures including the installation of micro-generation technologies, insulation, new windows and the adoption of 'smart' technologies, all have the potential to improve the energy performance of older buildings, but also to compromise the historic value of existing structures. This project examines how ideas about heritage conservation, a set of beliefs about the value of continuity and tradition, exist in relation to ideas about the need for environmentally motivated changes to a range of historic buildings. The project aims to understand the cultural meanings and social dynamics through which heritage and energy futures are constructed, through a study of the attitudes, values and beliefs of a range of building professionals and clients involved in renovation and retrofit. The project uses a mixture of methods, including interviewing and sustained detailed observation in relation to case-study buildings, combined with analysis of the broader discourses and cultural understandings that inform the positions of the professionals and clients involved. The findings will help understand how perceived conflicts between historic value and energy efficiency can be managed and will be used to shape policy and practice in an important but under-researched area.