Telescope stability in observatory

I’m a new member of the forum, in the process of building an observatory to house my 18” Obsession telescope (#1910). It will be a small one-story building, using an AstroHaven 12’ dome mounted on the flat portion of the roof. The problem my builder and I are facing is stability of the telescope. A pier is not practical. So we’re looking at structural approaches that will keep the roof (= floor of the dome) steady when I or others walk on it. Will appreciate suggestions from anyone with experience in a similar situation.

I don't have any specific suggestions, but however you build the floor, the area the scope sits on should be somehow separated from the area you walk on. Depending on your existing structure that may be easy - or not! - but good luck and I hope you find a straightforward and relatively inexpensive solution.