In my old house I did several runs of cat5 both in the crawlspace, and the attic, when installing cameras. I recently moved to a different house. I wasn't thinking about wiring at the time, but now I realize that (1) there's no installed ethernet wiring anywhere, (2) there is no attic (the ceilings go right up against the roof) and (3) there is no basement or crawlspace underneath. Architecturally the place looks very clean right now, so running exposed wiring on the outside of the walls is going to look bad and get some pushback, I think. There are regular AC power outlets in each room, as you'd expect. My experience with AC powerline modems was not great in the past, but I assume (apart from wifi) that's my best bet here?