My hens jump so their perches are about 4 feet off the ground, plus a shelf about 2 feet up. I use a garden shed because it saves me stooping to clean it. I have vinyl on the floor bigger than eh shed which is taken out weekly, hosed down, dried off, diatom thrown around the shed, sprayed with mitekill, then the vinyl put back. A plastic box filled with wood shavings serves as a nesting box. I have 11 hens, the shed is a 6 x 4 x 6 ft high. The run is 36 ft x 12 ft, and they free range for a few hours each day in a half acre grass paddock with shrubs along two sides and a burn along another.
HTH