On Tue, 24 Mar 2020 18:54:28 +0000, John Rumm
wrote:

On 24/03/2020 18:23, Caecilius wrote:
I'm extending a lighting circuit to add a couple of wall lights on the
1st floor. I've got the cables laid from the loft down to the back
boxes for the switches and outlets for the lights, and now I need to
connect the new circuit to the existing lighting circuit.

Is it acceptable to spur off the existing lighting circuit at the most
convenient point, or are there rules to follow when deciding where to
spur from?

Yup, although the circuit type is called a "radial" - you should not
take the term too literally. It doe snot all need to be a single chain,
and its perfectly acceptable to have branches as and where required.

Most of the diagrams that explain how to add a lighting circuit show
it coming from the last junction box / ceiling rose in the circuit. I
don't know where the end of my lighting circuit is, and sods law would
ensure that it's a long way away from where I want it. I don't want
to be drilling or notching joists if I can avoid it.

When wiring a new circuit that is often the easiest way to do it, and
also keeps the number of cables entering each JB / rose etc down.
However for extending, go with what ever works best for you.

Thanks. It's useful to get confirmation, as real-world experience
often differs from the neat and tidy diagrams.