BS 7671:2018+A4:2026 — IET Wiring Regulations 18th Edition Requirements for Electrical Installations (The Orange Book) BS 7671:2018+A4:2026 is the latest edition of the IET Wiring Regulations and provides the requirements for the design, installation and maintenance of electrical installations. Amendment 4:2026 introduces significant changes across a number of areas of BS 7671, making it important…