I don't know exactly how my outside electrics will pan out - but I can see some definates:
3-4 double waterproof 13A sockets under the bungalow eaves on each side of the bungalow (that's 1 per side). For misc use and maybe a temporary small shed feed via a centenary for a light and dehumidifier.
Possible long term 20 or 32A feed to a small wooden workshop.
Some random outside lights - 6A
Future pond supply (waterfall, lights) - 6A probable.
The max load of all of that is unlikely to exceed 32A (workshop heater plus powertool plus vacuum). I am not going to be mig welding at the same time as running a shed full of tools and heater!
I bought, speculatively, when I installed the house CU a Double Pole 32A Type B RCBO - with a view to the workshop supply. Double pole allows the possibility to TT the external circuits, but I doubt I'll bother with that.
Idea ==== Rather than wedge more RCBOs in the main CU, I am thinking it might be quite sensible to run this as a distribution circuit to a small 2nd Cu with MCBs for the various final circuits.
I'm well aware the MCBs will not discriminate well with the main RCBO - but that is not a concern - if the "outside" trips, it trips. The MCBs allow suitable cable sizing for each circuit and for partial isolation (partial because the MCBs are single pole) whilst remaining flexible and cost effective.
Any alternative ideas?