Did you look at the cozy legs heater? It's flat and it's cheap but it works really good. That's what i did have until i let the mother in law borrow it and it never came home. It wouldn't do for a huge area but it would definitely take the chill off. BTW the heater was ment to warm legs under desks so it's pretty darn safe.
My coop wasn’t originally a coop. It’s pretty big and wide open inside. I might need 4 of those heaters to take the chill off.
Gonna try and get some work done out there tomorrow. Try and shore up the wonky rafters. Get a real temp and humidity reading. Chase the little broody around to break her so I don’t have to bring her in.
And I have 15 chickens... so not exactly a house flock.