Boilers and their associated equipment have evolved dramatically over the last 25 years and Commissioning Code B has been comprehensively revised to take account of these changes. The new Commissioning Code reflects modern technology and statutory changes, as well as the growing realisation that many key decisions relating to the construction process are taken in the very early stages of a project. The Code therefore gives the strongest encouragement to designers and clients to consider commissioning and to seek specialist input from the start.