Start with the largest item.
Measure your mower, ATV, workbench, shelving, or equipment at its widest and tallest points. Include handles, attachments, and the clearance needed to turn or walk around it. An opening that is wide enough for the machine may still leave too little room to maneuver inside.
Compare three useful starting sizes.
An 8 × 12 listing has a nominal footprint of 96 square feet; a 10 × 16 has 160; a 12 × 24 has 288. Those figures are width multiplied by length, not a promise of usable floor area. Walls, door swings, porches, loft access, and model dimensions change the space you can actually use.
Understand Derksen measurements.
Derksen buildings 12 feet wide and larger are measured across the eaves because of transportation regulations. Smaller widths are measured from the outside corners of the walls. Ask for usable interior measurements and clear door dimensions for the exact model before buying.
Lay it out before you order.
Use tape or cardboard to mark the largest items and a walking aisle. Think about what you use every week versus what can go overhead. Visit the lot to compare the actual floor area, entry layout, and storage access.
Check the yard and the delivery path.
A building must fit its final location and the route into it. Check gates, turns, slopes, overhead clearance, drainage, and local setbacks with the appropriate people. Send the building size and delivery ZIP code so the route and site can be reviewed.
Sources & next steps
Building and price examples use Ozark Shed Co owner-supplied information and the published dealer listings reviewed October 29, 2026. Model and program references: Derksen warranty overview and Derksen rent-to-own overview. Confirm current terms for your order.