We are moving into detailed design stage of a new off grid house. 

It will be single-level and all Structural Insulated Panel construction.

Including a steel SIP panel roof which is also the ceiling all in one (and not great for cutting holes for downlights or even wires and pipes). 

So the current hope is to use LED lighting throughout, powered by DC more or less direct from the batteries. I imagine broad ledges around all the walls, concealing LED strips (lighting the ceiling from below) and in some places, LED downlights also in the ledges. 

We will also need air moving fans and water pumps, both of which I imagine use DC. The house will be so well insulated that I don't expect to need much heating (if any).

I quite like the idea of wireless switches (because they require less wiring, and a bit because they might allow for some automation like timers, PIR sensors). 

Has anyone gone down this road recently? I would really like to learn from your experience (and then share mine). 

Thanks

Graham