On buying a new house:
Work out the maximum number of cables you will run point to point around the house (audio/video, rf, ethernet, automated lighting, USB etc). Buy ducting twice the size you think you will need. Run it around ever room, over doors, through walls etc.
The OFSO's house is like that. Ducting is fairy discrete. Answers to rare complaints from wife: "do you or don't you want audio/video, rf, ethernet, 12v LED lighting etc, where you normally sit ?"
There ain't no answer to that.