Building a pole barn can be the perfect solution for everything from a woodshed to a full size livestock barn. Some call it timber framing.
Using natural shaped poles or finished beams and columns is a fast way to construct a building of just about any type. Your first considerations should be size, restrictions, and local building codes. Eliminating the first two, and if building in an area where codes don't apply it is still best to build to code. The codes give you a guideline that will help you design a safe structure.
Your pole barn can be designed as you build it, but it is best to always have some type of drawing to go by. Make a rough sketch of what you have in mind. It is easier if you use graph paper with one-quarter inch squares. Let each square equal one foot. The squares will keep you accurate enough and you will have an idea of how things will be laid out.
For simple terminology, anything standing vertically and supporting a load is a column. The large pieces that are horizontal are beams. Using finished lumber will make it easier to build uniformly. If your barn is going to be very rustic than you can use anything from used utility poles to the trunks of cedar trees.
Set the columns in concrete and a few feet deep depending on the size of the barn. If you are going to have a concrete floor you can still pour it after the columns are set. If the concrete floor already exists mount the columns with metal brackets attached to the floor. Attach all the columns and beams using large bolts through holes you have drilled as needed.
If you are worried about building a roof and rafters, a truss company will be glad to either measure your pole barn or build rafters for you based on your measurements. They should be glad to advise you on the proper methods of truss installation.
When everything is framed and the trusses are mounted you can decide on the type of roofing and siding you would like to use. It will be necessary to place smaller lumber between the pole framing as needed to support your siding and roofing materials. The supplier of these materials will also be glad to advise you of the proper framing for their installation.
Doors and windows can be installed as you are placing the siding. Any electrical or plumbing should be done before you place insulation or finish materials on the inside walls. On most pole barns, the inside wall is just the other side of the outside wall.
By designing as you go you can make it as plain or as fancy as you like. I have seen pole barns that looked just like any other building until you went inside. That's the beauty of pole barn construction.