Stay within reach of the hose. Choose a spot away from drainage swales and roof overflow. Avoid low spots where water can stand or pond. Leave plenty of room to access with pitch fork and wheel barrow. The area should be from 6'x6' up to 12'x9'.
Large yards use larger open air designs without covers.
Large doors are better than small ones. Three stage systems are best, but only one, maybe two bins are active at any given time. The three stages are stockpiling, active composting, and curing. Curing piles do not need bins. Since active composting is a batch process, it requires a full bin of material and this usually requires stockpiling.