Home – Blog – Metal Buildings – Steel Building KB 1 30 X 40 X 12 Steel Building KB 1 30 X 40 X 12 / Metal Buildings, Steel Buildings / By Craig Heineman Steel Building Specifications: 30X40X12 (3) 10X10 Doors (1) Walk-in Door (1) Standard Window (1) 12X40 Enclosed Lean-to