Our runs are just covered with chicken wire but for an inexpensive roof that can handle snow load and won't sag with heavy rain, I would probably go with metal panels and make sure they're installed on a slant. They are about $15 a piece in 3' X 8' sections and you can choose colors too.
Lol I understand! We started with 6 and now have many many more than that now
The general "rule" for space for standard size chickens is 1 foot of roost space per bird, 4 square feet floor space per bird inside the coop, and 10 sf per bird outside. You can never go wrong with too much room for the birds' well- being. Too little room and crowding can cause problems like aggression which usually results in injury to the more submissive birds in the flock.
For winter and summer comfort, all our coops are insulated. We've used standard R-13 insulation in some coops and then covered it with osb or plywood, and we've also experimented with layering feed bags in the walls and ceilings and sheeting it with plywood or osb. The feed bags work pretty well actually!!
You always want ventilation in your coops even in winter. It sounds weird to have something open when it's cold, but chickens produce a lot of moisture from breathing. When they're on the roost at night, this moisture wants to rise with the warm air but if there is no way to move that moist air away from the birds, it can hover over them causes frostbite on the combs. So the idea is to try to move air with ventilation. We use a variety of things like vent covers used in homes on your heat outlets like on our small coop:
We don't heat any of the coops and for adult birds we use heated dog bowls for winter waterers.
For chicks, we use brooder heat plates- love them! Much safer than heat lamps and the chicks do excellent with them. For little ones waterers, we made cookie tin heaters for about $8 each and set the chick waterers on them. They worked great!
I think summer heat is just as hard on the birds as extreme cold. Shade is important and if you have black or dark colored birds, they will need it for sure.