Buildings with numerous and/or relatively large wall openings
Figure 1: The numerous, equally-spaced overhead doors of mini-warehouses are ideal for post frame.
Figure 2: Large, equally spaced windows are well-suited for post frame.
Figure 3: Post frame easily accommodates the size and relative location of door and window openings in this building.
Windows and doors in a post-frame building that are narrower than the post spacing typically do not require structural headers, since roof trusses/rafters in most post-frame buildings bear directly on the posts. Elimination of structural headers enables elimination of trimmer studs (a.k.a. jack studs, shoulder studs) and other special structural members required to support the headers.
Removing headers and their supports not only saves money, but results in an enhanced thermal envelope when framing members are replaced with thermal insulation. Additionally, fewer framing members mean fewer cracks for air infiltration.
Mini-warehouses (figure 1) and service garages typically have several equally-spaced and equally-sized overhead doors making them ideal candidates for post frame. In these buildings, posts are often used to frame both sides of the doors.
Replace the doors in a mini-warehouse with large glass panels, and you can understand why post frame is also ideal for retail stores with large glass facades like that shown in figure 2. In general, any building with large, regularly-spaced door and window openings is an ideal candidate for post frame (figure 3).