Your esssential service like ... alarm CCTV ...router etc ... make sure they are "not" connected to an earth leakage unit.

The way i would do it ... a sub DB for the essential services ...inverter (compatible with solar for future) with a litium battery ... feeding a sub DB ... and plugs fed from the essential service DB ... are blue (not red) the plug which has a flat spot on the eatrth pin.

Put points under the top kitchen cupboards ...even if it is just a pipe with no wires ... people always want lights under the cupboards.

Your bright sparkie should be telling you all this info ... if he knows what he is doing (has the experience)

The stuff they dont teach you at college.