One of the best ways to increase the usable floor space of the attic in your pole building is to add a dormer.
Dormers are commonly used to increase the usable space in a loft and to create window openings in a roof plane. Dormers can be made functional or non-functional as well.
They increase headroom as well as provide daylight and fresh air. They also make previously dead space fully functional, and it doesn’t change the footprint of the building.
If your building will have attic space or a loft area considering dormers might be useful for providing light and ventilation.