There is a requirement for the development of new business models to facilitate, develop and construct the next generation of energy-efficient buildings. The development of such business models necessitates an in-depth understanding of the energy efficient building marketplace. To date, the literature in this space has been notably fragmented, and there is a dearth of research, which systematically addresses the energy efficiency and building retrofit industry. This paper presents work carried out under the FP7 supported project ‘UMBRELLA’ aimed at analysing and understanding the interactions of various actors within the energy efficient building market. The paper forwards a multi-disciplinary analytical framework through which to understand the multifaceted nature of energy efficiency projects. First, key actors at the different stages of the energy efficiency building projects are identified and characterised. These are then mapped through a mixed- methods approach, including concepts such as social network analysis. Concepts from disparate bodies of literature including value chain; value network/constellation; stakeholder analysis and business ecosystem are then applied to develop a systematic means of assessing value creating strategies and trends amongst identified stakeholders, who are classified according to recognised business ecology typologies, including keystone, hub, flagship and niche stakeholders. A series of in-depth interviews with stakeholders then facilitates the triangulation of research findings. Through a comprehensive mapping of the marketplace through these means, it is aimed to develop an understanding of the drivers and motivations of key actors involved in the energy efficiency industry. In this way, the paper contributes to an understanding of the perspectives of multiple actors in a complex industry, and forwards a novel analytical framework.