If I had a monster snake I would just let it have free range in my living room and just put heat lamps in the entryway so the snake would chill there most of the time. Then if anyone ever breaks in... most people will brave a dog, but how many people would brave a 20 foot snake?
Now to be serious. I have seen people convert walk in closets into "walk in enclosures" and thats about all the help I can offer lol