It is getting to the point where I am ready to install my main CU so just checking for any "gotchas" that I have not considered.

The unit I am going for is this

https://www.toolstation.com/mk-metal...er-unit/p77771

It has most of the MCBs I need and what is not there I can cannibalise from my existing CU. The CU will be populated as follows;

100A main switch

Garage - MCB with a 10mm2 T&E feed for now a 40A MCB. This will not be RCD protected as it will be run through voids or surface mounted. The feed is probably a bit overkill for now but I am looking ahead to possible EV charging. The garage does have an RCD in the garage CU hopefully restricting any problems to it rather than tripping the main CU.

Alarm - 16A MCB with 2.5mm2 T&E this feeds a couple of sockets in the loft for the wall wart PSUs for the alarm again not RCD protected as cable will run through voids and surface wired.

RCD 1 80A

Kitchen - ring main with 2.5mm2 T&E with 32A MCB
Lights - This is the main light circuit 1.5mm2 T&E with a 6A MCB
Hob - This is a 3.7KW induction hob which I am hoping to utilise the existing 6mm2 feed to our existing hob just transposing it to its new location. I will probably use the existing 32A MCB although a 20A should do
Oven - 5.6KW Like the hob I will be using the existing 6mm2 feed and 32A MCB

RCD 2 63A

Ring main - This is the rest of the house (bungalow) 2.5mm2 T&E & 32A MCB
Kitchen lights - 1.5mm2 T&E & 6A MCB
Boiler - 2.5mm2 & 16A MCB just in case we ditch the combi and go back to a system boiler with a possible immersion heater.
Shower - This is a temporary circuit as the shower will be replaced with a digital type when the bathroom is done over so I will utilise the current 4mm2 T&E & 32A MCB till then.

This will leave me with 5 spare ways two might get used with a surge arrestor if I decide to implement the full 18th Regs. However, seeing as these are rather expensive and seem to be optional the jury is still out on that one. As far as I know I have never in my lifetime of ownership of houses ever suffered a lightening strike or a surge but having said that the gods of mayhem will have one lined up as soon as I get this CU installed😵..

Richard