I can't speak about Bielefelders, but in general, the activity level of the bird is very important, so is personality. For example, I had andalusians, about 4.5 lbs per hen. They needed a lot of space because they're not super nice to each other and a bit nervous, and like to roam. I had amberlinks that were about the same size as the andalusians, and they were so calm you could put them in a smaller space than the andalusians.Bluebaby, question for you, or anyone. If 10 sq ft per chicken is the general rule of thumb for minimal run space for standard chickens, what is the minimum for Bielefelders? They are so much bigger than most chickens. Do you use a different rule of thumb for run and roost space for them?