Would routing it up to the loft be extra pipe run that isn't really needed? I just need to decide if it's a silly idea to put the master bedroom wall unit above our bed, and therefore directly over our heads, or if we should put it on the wall between the windows, which also means it'd face the landing a bit. If we wanted it on the south wall the loft run would be best I guess, but otherwise those three rooms could be served from the east wall and just run directly along the path at the side of the house? The living room run similarly could just run along the back wall and then around the other side?
I think the outdoor power supply is just tapped from the kitchen sockets. I'll be able to find out once the sale completes etc. I think the preference would be to run a dedicated line with rotary isolator though.
And thanks

I'll feel happier in a few months when we get keys in hand, plenty to go wrong before then