After moving, we found that we ran into numerous problems with EM fields for a variety of reasons. We eventually found the sources and had the problems corrected, but with quite a bit of unnecessary expense and down time. If I had to do it again, I'd bring in the vibration and field experts during the design stage. Richard most e.m. units are at ground floor or basement level so consider the risk of flooding. But at the very least it should be possible to isolate the electrics to microscope and lab in an emergency.
Flooding is less likely than vibration and magnetic fields but it does happen and can be disastrous.