At the previous company we were forced to move the office out of one factory into the adjacent one after a flood (fortunately the raised floor in the computer room meant nothing was damaged).
After pointing out that trying to cram the computer room and two people into a one-person office would be totally impractical, and possibly even illegal (insufficient volume per person) we were offered a semi-redundant toilet as an alternative. As part of the refurb we insisted that a dividing wall was removed, only to be told, "We can't, it's supporting a 1,000 gallon water tank!" Said tank turned out to be sitting on wooden beams between two walls and could easily have come down at any moment. We got it moved!
We also then discovered that there was an internal valley gutter running over the other end of the new room right above the comms rack. It only overflowed if the rain was really heavy... A year or so later and it was eventually fixed and we could remove the polythene sheet.