My greenhouses were at about the same elevation as the surrounding yard (the 4x4" foundation is about 2" above grade), but having the flooring built up 4-6", there is never water standing. The periphery of my greenhouses is also mulched and there are evergreen shrubs between the walls of the two greenhouses and the paver walkway that goes between the greenhouses.Again, you are not growing plants that I do, so your flooring needs are nothing like mine. That's why I never chimed in..........just didn't think my layout would be as practical for you, Thomas.
These photos are 2.5 yrs. old. Its in the dead of winter, thus the solar material covers. The landscape plants (Euonymus 'Manhattan') are now 3' tall and I keep them trimmed to that height. By the way, the 'Manhattan' is as close to a near-perfect landscape plant as I have ever grown.
