Fuel cells have the potential to achieve high levels of energy efficiency, with lower emissions of greenhouse gases compared to more conventional systems. This BSRIA guidance provides a review of the technology relating to fuel cells and their potential use in building services applications. Includes information relating to: fuel cell technology; benefits to building services; applications for building services; operation and maintenance; health and safety issues; codes and standards; potential developments. Provides six case studies demonstrating the application and evaluation of fuel cells.