Coop building depends on how many birds you have and personal choice. Generally, standard sized chickens need 4 square foot per bird inside. If you only have a few birds, you might want to look at the chicken tractors because they are the cheapest and easiest to build. The chickens also will need roosts to sleep on and nesting boxes for laying eggs and brooding. If you need more info, then we need more info from you, like how many birds you have and what are the deciding factors in coop construction. Is cost the only thing you're looking at? Do you need something mobile? Do you already have a fenced run in mind? What kind of chickens are you getting/do you have and what will they be used for (eggs, meat, brooding, pets)? Chickens tend to be comfortable as long as they are warm, dry, have something to eat and scratch and there's nothing trying to eat them.
