Part P says you can replace a single circuit

[zaax]

switch off circuit. Cut though wire. Circuit now damaged. Replace, with new sockets etc as required.

If a ring main is replaced over a few years...

[John Rumm]

You can extend an existing circuit with new sockets etc anyway. So no need to go cutting cables.

Tis fine, just you can't (in theory) install a new one.

[john]

Who is ever going to know unless you take out a full page advert in the national newspapers? Who even cares?

[George (dicegeorge)]

dont you need an electrical test certificate when you're selling a house these days, which would fail if I rewire my bathroom and kitchen? and should we use the new colours of wire?

george

[John Rumm]

Not as such AFAIK (unless a HIP requires one).

If you disclosed that recent work has been done on the place then they may take more interest. Having said that the standard sellers forms allow for the possibility that paperwork is "lost".

Why would a test fail if you have done the work correctly? (or am I missing your point)

Yes, why not.

The colours don't date work as pre or post part pee anyway since new colours were allowable before, and old colours allowable after.

[Frank Erskine]

Why should it fail? If you do the job correctly you'll likely get a better result than so-called 'professionals', simply because you know that you are doing the job for your own benefit and safety rather than as a money-making venture, so you will use decent quality wire/cable/accessories/miscellaneous 'bits and pieces', and follow the relevant legislation.

If someone has to test it, it makes no difference at all who carried out the work. As long as it's a 'satisfactory' installation the certificate will (should!) be forthcoming.

Colours of the wires don't affect safety.

Regarding selling a house as you mention, forget that you intend to sell, treat the house as your own and develop it accordingly, then you have nothing to hide from a potential purchaser.