Eek! Swimming pools in private homes freak me out. Sounds like a pefect setting for a real-life game of Clue! (While we're on the subject, that movie has great costumes. Miss Peacock is in muted rust, Mrs. White is in all black, etc.)
I doubt that anybody sneaky enough to own one would be too concerned about building code. But I agree. The best houses in the world are ones with secret passageways. I also want a trapdoor in the kitchen, right above the swimming pool.