Regulations, Codes, and Compliance
This domain separates statutory law from standards and tests whether you know which document imposes a duty, which gives a means of compliance, and what to do when a client asks for something non-compliant. Precision about shall versus should earns marks.
Law and standards
- Statutes impose duties: the Health and Safety at Work etc. Act 1974, the Electricity at Work Regulations 1989 (regulation 4 on systems and equipment, 5 on strength and capability, 14 on live conductors and 16 on competence), together with PUWER, COSHH and local building regulations such as Part P in England and Wales.
- BS 7671, the IET Wiring Regulations, currently the 18th Edition with Amendment 2 dated 2022, is not statute. Following it is evidence of compliance with the statutory duties; IEC 60364 is its international parent, HD 60364 applies across Europe, and NFPA 70 governs in the United States.
- Within the standard, shall is mandatory and should is a recommendation. Departures are permitted only where safety is not compromised and must be recorded on the certificate.
Competence and certification
Design, installation, inspection and testing must be done by competent persons. Notifiable domestic work goes through building control or a registered competent person scheme. New work takes an electrical installation certificate, like-for-like alteration takes a minor works certificate, and periodic assessment takes a condition report.
Worked example
A client asks for a 13 A socket in a bathroom 1.2 m from the bath. It would sit inside the 3 m restriction measured from the boundary of zone 1, so BS 7671 does not permit it there. The compliant answer is to refuse that position and offer a shaver socket to BS EN 61558-2-5 or a socket outside the 3 m zone, while ensuring 30 mA RCD additional protection for socket outlets up to 32 A. Supplementary bonding of the location may be omitted only where every final circuit of the location is 30 mA RCD protected, disconnection times are met, and extraneous-conductive-parts are bonded to the main earthing terminal.
Traps that cost marks
- Claiming that BS 7671 is law rather than a means of demonstrating compliance.
- Mixing NEC rules and cable sizes into a BS 7671 installation, or the reverse.
- Leaving a departure undocumented instead of recording it with justification.
- Quoting an out-of-date amendment for RCD or bathroom requirements.