From the September 1997 issue of

Bee Tidings is a cooperative publication of the University of Nebraska Cooperative Extension and the Nebraska Honey Producer's Association.
Minimum area required: Any lot can have one hive, but homeowners are limited to one hive for every 1,500 square feet.
"When you consider the tiny space battery hens make do with, you realise that hens do not need a lot of room but we want to give them as good a standard of living as possible.
Hens don't require a lot of room for sleeping so as a rule of thumb, a house just 3 feet by 2 feet will accommodate 4 hens comfortably, possibly 6 smaller hens.
For a run they need about 6 feet by 3 feet for 4 hens. Obviously if you can let them run further and scratch about naturally then that's great."