I built a pole barn last year to put my boat, enclosed trailer, and pickup in, 3 bays 32' wide and 21 foot deep. Used 8 telephone poles (cost 0 but had to go get them, cut to size). A friend brought his backhoe over and removed a tree or two that was on the site, then set the poles in the ground using the backhoe as a crane into holes I augered out with the tractor then made bigger with post hole diggers. I tied the 4 front posts together with a doubled 2 x 8, lag bolted to the posts, then did the same with the back 4 after cutting them 2 1/2' shorter then the front. 2 x 12 x 20 yp joists run front to back,2' OC, solid blocking down the middle, 1 x 4 runners every 2 ft, then topped it off with 21' long sheets of metal roofing. Another friend brought his skidsteer out to smooth out the ground under the shelter, then a trip to the gravel pit with a borrowed dump trailer, 11 tons of crusher run. barn was built on a budget but I did trade out some electrical work for the skidsteer work and the borrowed dump trailer. Going to add a wood shed this year