Good job using what yo had on hand. It would help to know what you did inside the hen house itself. And I think more ventilation would be better on the coop. Do you have pictures of the nesting area and the roosts?
I think this is one of the easiest coop builds I've seen. I like the large vent holes at the top and sides. I know your 3 hens are happy laying in the dark private spaces you provided and I believe they are safe at night when the coop door is closed.
