I am to install central heating in my house and need a single socket
for the boiler to be close to it.

Can anyone advise which is the better option -

1) To take a spur from an existing socket on a ring to this additional
socket or

2) To take a spur from a junction box intercepting the ring main. I
understand from this that I need to remove the sheathing on the cable
and strip away some casing to leave about 1/2" of the neutral and live
exposed and connect this without cutting the 2 wires. The only wire
that needs to be cut in 2 is the earth wire and then linked to the
spur.

I think the junction box would be the easier option as I could take a
feed from the cable in the ceiling as the socket is needed half way up
a wall. The socket spur would involve a wire going down from an
existing socket into the cellar, along then up the wall.

Any advice would be greatly appreciated and many thanks in advance.