Advice needed on expanding electrical consumer unit

On 18 Jan 2006 16:13:35 -0800 someone who may be snipped-for-privacy@lycos.co.uk wrote this:-

That rather depends on how many ways your current consumer unit has and what the precise configuration is. Assuming you can get a suitable new consumer unit then the answer is yes. This is neater, but your electricity will be off while the whole replacement is done. You may be able to re-use your existing protective devices in the new unit, if you get the right one.

The normal way of doing such things is to insert a junction box in the meter tails. From this new cables go to the new consumer unit. This has the advantage that all the new wiring can be done and tested before the new consumer unit is connected, or the new consumer unit can be connected and the wiring done later. However, it is not as neat.

You have four options really:

1) Replace whole CU with another that has more ways

2) Split the meter tails with a service connection block and add a new CU in parallel with the existing one

3) Disconnect a circuit from the old CU, fit a suitable MCB and use it to feed a cascaded CU that then feeds the new circuit plus the old one removed from the original CU.

4) See if you can logically combine two existing circuits in the CU to free up a way.

1) is expensive, but gets you the chance to upgrade and bring the whole lot up to modern standards. 2) is often the better way forward, less hassle / cost. 3) is common if you want to have the new CU some way from the original. 4) only works is you have circuits that can sensibly be combined...