2 WAY SWITCH WITH A STRANGE SUPPLY

[PARTPISGREAT]

Can anyone advise me?
I'm removing some wiring from my garage before it's taken down and replaced with an extension. I've removed some outside lights which operate from a 2-way switch. Here's where the strange bit is that I've never seen before. The switch in the house is part of a 2 gang switch. One switch is being used as a 1-way switch, the other controlling the lights outside. However, the 2-way switch only has 1 T&E cable into it (which goes to the other switch), the actual power or COMM is taken from the adjacent 1-way switch by means of a short wire connected between the two COMMS in the switch. I can see exactly what it's doing and I can see that the Neutral for the lights is connected into the ring in a different place.
Is this safe? It just looks a bit amateurish. I'm not a professional, so I might be utterly wrong.
For those of you who want to remind me about Part P and give me a lecture, please do not respond. I know all about it and the rebuild will be done by a proper sparky. Also, to make it easier, I've not mentioned the earths which are all present and correct.

 

[ban-all-sheds]

1) I can't grasp exactly what combination of 1-way and 2-way switches you have. Sounds like a 2-gang 2-way, with a 1-way switch next to it - yesno?

2) If you are rippping it out and having it all replaced, why worry about it?

 

[PARTPISGREAT]

Sorry, I've not really explained it very well. (and after checking the following, I'm possiblynot making it easier)
There is only switch in the house and it is a 2gang 2 way. One of the switches (call it S1)controls the lights in the room and although the switch itself is 2-way, it is only being used in a 1-way operation for the room lights. The second switch is then fed the live from the adjacent switch (S1)with the T&E taking the switched live to the other 2 way switch.
As this is in the house, I'd like to re-use the wiring in the switch for my new outside lights. If the above is not safe, It means I'll have to start removing plaster for the sparky to put in a second wire in a room that should be unaffected by all the building work.
Does this explain it better?

 

[PARTPISGREAT]

Sorry, I've not really explained it very well. (and after checking the following, I'm possiblynot making it easier)
There is only 1 control in the house and it is a 2gang 2 way. One of the 2 switches (call it S1)one controls the lights in the room and although the switch itself is 2-way, it is only being used in a 1-way operation for the room lights. The second switch is then fed the live from the adjacent switch (S1)with the T&E taking the switched live to the other 2 way switch.
As this is in the house, I'd like to re-use the wiring in the switch for my new outside lights. If the above is not safe, It means I'll have to start removing plaster for the sparky to put in a second wire in a room that should be unaffected by all the building work.
Does this explain it better?

 

[ban-all-sheds]

OK - the 2-way half is wired as per the "conduit method" (see third diagram here).

Nothing wrong with that provided that both the lights get their neutrals from the same circuit. This is very important - see here.

 

[PARTPISGREAT]

ban_all_sheds - Thanks very much for that, I feel much better knowing that it is an accepted practice. Thanks for taking the time to explain.

It's been done properly - although I have 2 lighting circuits, (upstairs and downstairs), all of the connections went into the downstairs circuit.

My wife will be pleased that the utility room won't be full of plaster dust!