When the architect designed our penthouse suite he didn't think he needed to include specifications for what to do about the plumbing as he assumed the builder would just sort it out using his common sense. The builder, however, has no sense at all. He just left it to the plumber. He figured, oh well, I'll just put pipes where they'll go, making it up as he went along. So no provision was made for the pipes to be integral; they are on the outside of the building.
We've since had to renew the plumbing in the old flat because the pipes had corroded - this has meant our new plumber having to add to the circumlocutory nature of the supplies of water to bathroom, toilet and kitchen. Here's a short movie of the result.