BSRIA BG02/10 Commissioning Water Systems (BG2/2010) This revised guide supersedes AG 3/89.3 Commissioning Water Systems application procedures for buildings, it provides the latest information on water commissioning for practising engineers, and complements CIBSE's updated Code W. Proper commissioning enables engineering systems to operate at optimum performance providing the building users with good quality internal environments. This guide encourages designers and clients to consider the requirements for commissioning at an early design stage of a project. This will ensure that the statically completed installations are fully checked and proved. This guide presents a detailed description of the practical aspects of commissioning procedures in a step-by-step format.