fjk61011 wrote:

If our consumer unit is moved by about a metre/3' 3" the upstairs
circuit cables would be too short to reach the CU. Would all the
upstairs cables have to be replaced or could the cables be extended by
jointing cables?

They could be extended, for example by crimping, using a *proper*
ratchet crimping tool like this

http://media.digikey.com/photos/Paladin%20Tools%20Photos/MFG_1357.jpg

Not a cheapo tool like this

http://cache1.smarthome.com/images/89256.jpg