Electrical supply to new extension

[Bodgitnscarper]

Hello,all.

Could someone please advise me with regard to my extension build please?

It is a two storey extension to an ex council 3 bed semi (soon to be 4 bed).
We have made provision for the electrical supply to be moved from the internal wall at the front corner of the existing house, to the external side wall of the extension, in the form of a recessed meter box.

The consumer unit is presently located on the inside front wall, surface mounted.
All of the house electrics appear to go vertically upwards inside a surface mounted trunking.

I want to do away with the surface mounted trunking and move/replace the consumer unit to the extension utility room directly inside behind the new meter box.

What would be normal practice to achieve the link between old and new electrics?
I assume the first and last cable from each ring main will need to be replaced?
Is it necessary to have a full rewire?

Any advice appreciated. Thanks.

 

[flameport]

What would be normal practice to achieve the link between old and new electrics?

Depends on the circumstances, but in any event concealed joints between cables must be maintenance free types. Normal junction boxes and similar are not suitable.
Once the old consumer unit is removed, cables above/below it cannot remain where they are unless inside steel conduits or similar protection because there will be nothing to suggest cables are concealed in the wall.

I assume the first and last cable from each ring main will need to be replaced?

Possibly, although there are other options and most of the circuits won't be rings anyway.

Is it necessary to have a full rewire?

Probably not but given that every single circuit will have to be modified/extended/relocated and it will be a totally new consumer unit, this would be the ideal time to do it.
You should carefully consider what lighting, socket outlets etc. you actually want in both the new extension and existing rooms.

 

[Taylortwocities]

What you propose is notifiable work.. this would need to be done by a registered electrician or you'll not get a completion certificate from LABC.

Who did you tell the local authority would do the electrical work when you applied for the building notice?