3phase dis inb domestic setup

[J.C.E]

looked at a rewire of a 4storey property today (lower,ground,1st,2nd)
they is a 100a 3ph head on lower floor- and there is 2x seperate SP c/u (think there use to be 2x flats)

but is now going to be one house

best option?... to install something like a 8way 3ph amd3 dis board by the head on lower floor and have all my circuits off rcbo's off that (balancing the load evening across the phases)

probaly do circuit wise:

lower floor lighting 6a 1.5
ground lighting 6a 1.5
1st+2nd floor lighting 6a 1.5
lower ground power 32a 4mm radial
ground power 32a 4mm radial
1st floor power 32a 4mm radial(with 2x 3m2 UHF kits)
2nd floor power 32a 4mm radial (with 1x 3m2 UHF kits)
kitchen ring 32a ring/radial
Indcution Hob 32a 6mm
Oven 20a 2.5mm
MW 20a 2.5mm
I.H 16a 2.5mm
Boiler 16a 2.5mm
Alarm 6a 1.5mm
Smokes 6a 1.5mm

no 'building' work is being undertaken as in extensions etc- so no building inspector- would I need a system grade A fire system as a large house or will I be fine will LD3 (smokes in 4x halls and heat in kitchen- all interlinked)

 

[J.C.E]

this is the current setup before rewire

3phases from head >> MEM isolator

L3 goes into a henley in the trunking >>which feeds the SWA and that SP meter

the SWA then feeds another meter which supplys a c/u for one part of the house

and the SP meter in the picture feeds another c/u which does the rest of the house (via the orange pyro)

so the old 2x c/u are both on L3 100a

The house is now one- and the client wants one consumer unit in one place- nice and organised

I was thinking to start from scratch

take head tails (only from 1 phase)>> SP meter >> new 100a SP isolator

then a SWA from new 100a SP isolator>> a new hager 20+20 stacked consumer unit with rcbo on the ajacent wall (as the curved ceiling will look craap with trunking/cables

then just leave the other 2 phases unused at the head

thoughts