Professional Engineering organisations that deal with HVAC and other Building Services have members with interests in Building Simulation, facilitate relevant interest groups and technical committees, and provide sources of information. Such organisations include ASHRAE (American Society of Heating, Ventilating and Air-conditioning Engineers) and CIBSE (Chartered Institute of Building Services Engineers) in the UK. ASHRAE publishes information about Energy Simulation in its ‘Handbook of Fundamentals’. CIBSE has produced a useful document ‘Building Energy and Environmental Modelling Applications Manual AM11’