There are various intrusive wiring regulations in the UK. If I want to wire up a light extension I'm required to have this done by a suitably qualified person, or if I do it myself get it approved by a suitably qualified person.

Of course I'm sure that most people who know what they are doing ignore such rules, but they can become important if you have to make an insurance claim or want to sell your house.

So my question is, does anyone know when this becomes relevant to home made IoT devices? I have a solid state relay driven by an ESP8266 device controlling lights that I made. It works well. It's safe, properly made and properly insulated et cetera and it's using proper components.

But is this covered by the regulations? I assume that if I made this a device I plugged into a socket and then plugged a light into it then it wouldn't be. But as it's permanently wired into a lighting circuit, do I in theory have to get this approved by a "competent person"?

  • So you are interested in what cases you need approval for such a device? Dec 13, 2016 at 13:02
  • 2
    (I am not a lawyer) I would doubt that a suitabley qualified person (say an electrician) would stick his neck out for you and your DIY solution just based on looking at it ("looks safe?). OTOH going through full CE conformity marking and all attached regulations that cover electrical safety issues could sum up to multiple 10k€ so that is not a way either.
    – Ghanima
    Dec 13, 2016 at 13:44
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    I guess I'll do what I want in my own house, obviously taking appropriate care, but have a firm plan to remove anything if I ever want to sell.
    – jcoder
    Dec 14, 2016 at 12:52

2 Answers 2


You only need to start involving qualified people for fairly major work. Minor alternations can be done yourself so long as they are done properly. What you are proposing doesn't sound like it would require notification.

You can find out more about what is and isn't regulated in the Part P FAQ. Small alternations and general DIY work is specifically excluded, except in special circumstances.

  • It would be great if you could quote a relevant passage.
    – Helmar
    Dec 20, 2016 at 23:11

The regulations in the UK cover fixed wiring only, as far as I know. Replacing existing fittings is generally OK, it's only new or specific locations which are regulated. So if it plugs in, it's OK. If it's hard wired, I think it needs to meet the relevant standards.

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