A man by the name of Orson
Fowler wrote a book on octagon shape barns.
According to him it was better utilization of space,. It required less materials and less time to build.
This octagon barn was found in Kewaunee, County in Wisconsin. A huge advantage for Wisconsin communities along the Lake Michigan shoreline was that the octagon shape withstood heavy winds.
Most of the octagon shaped barns were built between 1880 and 1920.