Green Building Challenge (GBC) is a unique international research, development and dissemination collaborative effort to further understanding of building environmental performance assessment. The unique features of the GBC process are that it is ad-hoc with no host organization; it is based on national teams; it is self-funding; it depends on consensus amongst the participating countries; and it uses conferences as a focusing device. Other significant features include the roles and motivations of participants; working in subgroups; and the importance of networking and personal contacts. The future of GBC will depend on the success of many of these past operating methods. GBC has provided an important model for innovation strategies with high impact. It indicates that rapid and visionary work can be achieved through a consensus basis of researchers and practitioners, without layers of management or bureaucratic strictures. Its notable success lies in linking the research and practitioning design communities' interests through the development of national case studies.

• sustainability, environment

1. Emerging trends in building environmental assessment methods
2. Lessons learned, future directions and issues for GBC