Plans

I am not a structural engineer but I see no problem in you draing the plan and handing it over to an engineer for evaluation and engineering requirements. I have built "Oregon" barns and very similiar to this plan and had no problems with standard construction and no engineering and that is in Calif. Now they may have "upped the annie" and require engineering now? I would build a standard 2 story footing, and also, the interior posts should be on a continuous bond beam footing. We built the rafters in a truss like fashion using plywood gussetts..... Also on the outside of the barn was built shed roofs off either side thus increasing parking and storage and more shear strength. Barns are a good space saver and do go up fairly well. Some dormer options also make the upstairs more useful. (that is a dormer on either side in the center.....shed dormer...... jloomis construction and concrete.....