There are a few things to think about: How many chickens do you have? Do they free range at all or are they always in the coop/run area? How big is your space?
My girls' coop is only 4 x 8 and their roost is 4 x 4 but they free range from sun up to sun down, coming in only if they want to. I use the deep litter method, so need to clean and sanitize 2 times a year on the coop floor. I have a metal pan that is an oil drip pan from the garage that fits perfectly under my roost. I clean it 1-2 times a week. In the hot summer, more often. I find that keeping my coop clean isn't as much work as I thought it might be. And, it's fun to chat with the girls while I do.