Its a lovely size esp as they look to be big buns in the first place, What are the dimentions?
I think I would change the glass to perspex, as glass magnifies the suns rays and will make it very hot and stuffy and add more vents to the perspex, I would also consider addin a permenant run, as they can escape the heat if it does get too hot.
I would also want to change the bottom chicken with to welded mesh, as foxes can easily chew through the stuff that is in there now.
ETA - where do you put the water bottle?