The post-frame building concept is not new. For centuries, people throughout the world used posts embedded in the ground to fashion sturdy structures for residences and other uses. In all these cases, the limited life-span of poles in contact with the ground made them unsuitable for use longer than a few years, except in very dry areas or when rot-resistant strains of wood were used.
However, two significant technological developments in the twentieth century allowed the post-frame building to develop into a viable, long-lived structural system.

     First, pressure-treated materials that provided excellent durability, became available for the construction of buildings.

     Secondly, large, lightweight metal sheeting was produced that could span supports spaced several feet apart.

 

The large primary frames consist of square wood posts or columns and trusses which are typically embedded in the ground or surface-mounted to a concrete or masonry foundation and trusses that are typically spaced between 4 & 12 feet apart.

These primary structural components  are connected with smaller wood members (girts and purlins) to resist applied building loads.