Chickens should have at least four sq. ft. per bird, and preferably more, in a roofed weather and predator protected coop. It's not a 'sleeping area'! There will be times, during bad weather and predator visits, when the flock might be in for two or more weeks at a time. Too small, and nasty behaviors will happen. Your roofed run can be part of this area, if it's also predator proof. Otherwise, the coop needs to work for the entire flock.
Mary