This book is a complete guide to the latest edition of the IEE Wiring Regulations, BS 7671:2008. It provides comprehensive guidance on all aspects of electrical installation design, including the Electricity Safety Quality and Continuity Regulations. Derivations of the requirements are included along with the relevant formulas, data, installation design calculations, and examples. The Commentary also includes guidance on related subjects, such as the prevention of electromagnetic interference, allowance for harmonic currents, and the use of cable armouring. This is essential reading for consultants, electricians, installation designers and all those with a professional interest in the implementation and interpretation of the Wiring Regulations. Paul Cook is the author/editor of many IEE guidance publications, including the OnSite Guide and several Electrician’s Guides. Originally trained as an electricity distribution engineer, for most of his career he has been in electrical contracting, undertaking a variety of roles from design engineer to business manager. He is a Chartered Engineer and a Fellow of the IET.