DIY Doctor UK DIY Forums

Hi there,
I am sure there is a very simple answer to this but what is a common mcb configuration for split load consumer units?
I have relatively new wiring in my property but am having an extension and want to add a new loft lighting main, loft socket main, loft shower supply and garden supply.
My existing fuse board is 'packed' with circuits and hence i am installing a new one to rationalise the existing circuits and new the new ones stated above.

I am relatively competant in so far as i have replaced wiring, turned radial circuits into ring mains etc but what i dont seem to be able to find is what commonly is wired to the RCD side of a split load consumer unit.
I suspect the garden supply is a given and maybe the ground floor socket ring main as i may take an extension to the mover off this.
What else?
I don't see the point of a 7/8 split load unit just to add the garden and downstairs power ring on it.
Does it do any harm adding other circuits on it or will it be too sensative and cause odd tripping?

I can't believe i'm the only person to ask this question!!

Many thanks for your help in anticipation.

Before proceeding with this job please read our project on Part P of the building regulations. Adding new circuits and/or consumer units to a property requires more than relative competancy by law.