IET Guidance Note 7: Special Locations (BS 7671:2018+A4:2026)

IET Guidance Note 7: Special Locations (BS 7671:2018+A4:2026)

IET Guidance Note 7: Special Locations (BS 7671:2018+A4:2026) provides practical guidance for electrical installations where BS 7671 requires additional or different protective measures. Special locations often have higher risk profiles or unique environmental factors, so correct interpretation matters. This guide helps users apply the Wiring Regulations consistently across a wide range of specialist settings.

Designed for anyone working in special locations here requirements can vary – consulting engineers, electricians, electrical installers, inspectors and technicians – this updated edition aligns fully with BS 7671:2018+A4:2026. It supports clearer decisions during design, installation and verification, especially where modern systems introduce new sources, protective device and power distribution methods.

Updates include guidance on open-PEN detection devices, significantly revised guidance for medical locations, coverage of bidirectional and unidirectional devices, and new guidance around stationary secondary batteries. It also includes guidance on rating distribution boards with multiple sources, RCD selection, and Power over Ethernet (PoE), reflecting the realities of today’s building and infrastructure.

Key Features

• Special locations guidance aligned with BS 7671:2018+A4:2026
• Explains additional measures required for compliance in higher-risk or specialist environments
• For consulting engineers, electricians, installers, inspectors and technicians
• Guidance on open-PEN detection devices
• Significantly updated guidance for medical locations
• Covers bidirectional and unidirectional devices
• Includes guidance on stationary secondary batteries
• Guidance on rating distribution boards with multiple sources
• Guidance on selection of RCDs for special locations
• Includes Power over Ethernet PoE guidance