Adding a new light to existing circuit

Yes you can extend the lighting circuit to add a light in the en-suite. It would be preferable to install a new cable from the light fitting in to the new switch for the en-suite rather than trying to cut and join a cable because junction boxes should be accessible or maintenance free. If it's jointed in the ceiling void you won't be able to access it without lifting floor coverings and floor boards. The reason to feed the switch rather than the light fitting is to make it easier to wire the new light fitting. You only need to loop out of the switch with one cable, live feed in, switched live out and join the neutrals. This is my preferred method of wiring lights. The wire size just needs to be the same as what's there. It could be 1.0mm2 or 1.5mm2. Hope this helps. Roy

Hello, How are your existing earthing and bonding arrangements? Do you have the correct equipment to prove the circuit is dead once you’ve switched off? What type of light are you intending on installing? IP rated sealed, IP & fire rated down light? RCD protection in place? Will the light be within Zone 1 or 2 of the en suite, assuming it has a shower / bath. Yes you can do what you’ve asked, but there is more to it... We can only say so much. It’s always recommended to get an electrician to do the work for you. Regards, Carl.

If you need to ask questions like this you need to get a professional electrician to do the work.

Agree with all ,and note if domestic lighting under current regulations as your are altering it ,the alterations need to comply with current regulations which require all lighting circuits to be RCD protected at 30ma ,strongly advise getting a suitably qualified professional electrician do the work for you