I am in Ontario Canada,
My colony rabbits were in a 15 by 20 fenced area with several dog houses and a 6 x 6 shed they could shelter in.
My current breeding stock is individually caged a 10 x 10 section of a barn with 2 wire walls and 2 walls of cement block that goes up 4 feet with wire to the roof. In the winter I board over the wire to heat the room so I can breed year round and in the summer it comes down for better air circulation. My grow outs are in a colony pen with roof and a dog house for shelter.
A one sided run in shed would easily be converted to a rabbit barn. Position it so the prevailing wind is hits the wall and in the winter you can tack up some plywood to make it 3 or 4 sided, depending on the kind of weather you get, to hold heat and protect from the elements better.
As others have said, the main thing is to keep the rabbits cool in the summer, out of drafts, drifting snow, driving rain and keep them (and their food hoppers) dry.