Gas and electrics: who must be registered, and what DIY is legal

Any business or self-employed person doing gas work must be on the Gas Safe Register: regulation 3(3) makes registration the law for anyone working as an employer, employee or self-employed person, and the Gas Safe Register is the only class of persons the Health and Safety Executive has approved. Falsely claiming registration is its own offence, and illegal gas work is prosecuted by the HSE.

Unpaid gas work on your own home sits outside the registration duty, but never outside the law: regulation 3(1) says no person may do any gas work unless competent, and the regulations' definition of work expressly includes do it yourself activity and favours for friends. The HSE's competence bar is recognised training plus assessment, which in practice puts DIY boiler and gas fitting work out of reach: being allowed to attempt it without registration is not the same as being competent to do it.

In England exactly three kinds of domestic electrical work are notifiable under regulation 12(6A): installing a new circuit, replacing a consumer unit, and any addition or alteration to circuits in a special location such as the zones around a bath or shower. Notifiable work must go through one of three routes: a registered competent person who self-certifies, a registered third party certifier, or building control. DIY electrical work is legal in England, including notifiable work, and the folk rule that a homeowner cannot touch a consumer unit or add a circuit is wrong on the law: the requirement is to notify a building control body before the work begins and pay their charge, after which they decide the inspection and testing needed and issue the completion certificate. Everything outside the three notifiable kinds, like for like replacements, repairs, and additions outside special locations, needs no notification at all, though all of it must still be done to the wiring standard the regulations point at.

A registered competent person must give you a BS 7671 electrical installation certificate for the job and a building regulations compliance certificate within 30 days. On the DIY route, the building control body's completion certificate is the paper that matters when you sell. For hired work, check the engineer's Gas Safe ID card and registration before they start. A registered engineer installing a boiler self-certifies the building regulations side through the Gas Safe scheme, so the paperwork arrives through their registration body.