Thanks. That was my concern as well on the plexiglass (greenhouse effect).
When I say dirt floor, I guess I mean that the coop is on the ground and it's not raised up. (Which I now know was a mistake. At least we have it secured so that critters can not break in or dig under.) The floor is the dirt ground, but I do also use some pine shavings & dried leaf litter on the dirt in fall, winter, & spring. In the summer the chickens spend a lot of time outside & not in the run, unless it's very rainy, so during this time of the year I don't usually use shavings or leaves. And then if the ground gets wet I clean up and mix some PDZ stall refresher in the dirt. But it sounds like it would still be a good idea to use shavings & leaves in the summer anyway?
Groundwater per se doesn't seem to be the issue, But I think what has happened is, since the chickens dig to dust bathe on the dirt floor, and then they do the same thing on the ground right outside the coop, I've got some areas where the coop floor & the ground right on the other side has become too low, & also has too many depressions in which water accumulates. It also seems to me that there might be some water that gets onto the coop floor just under and around the door and outer walls for the same reason: water pooling in those spots has further lowered the ground level right there. To handle that problem I often get dirt from elsewhere on the property and haul it in. Ugh. (Should've built a raised coop.)
Overhangs: Great idea, which I only just recently thought of too, and placed right outside the coop door, to help stop additional pooling up right there. I'm trying to come up with ways to place others in strategic locations.
I'm also looking at gutters (if I don't tear this coop down and start over...).