Foundation expenses significantly affect the total cost of a metal garage. A concrete slab typically adds $4–$8 per square foot. For a 20×20 garage, expect $1,600–$3,200. Soil quality, frost lines, and site leveling needs may increase foundation costs, making it a critical part of budgeting.
- Concrete slab vs. gravel base: Gravel bases are cheaper but less stable. Concrete slabs offer long-term durability and support.
- Site preparation needs: Clearing, grading, or compacting the site can cost $500–$3,000 based on terrain.
- Frost line considerations: Cold regions require deeper foundations to prevent shifting and cracking.
- Anchoring systems: Slab-anchored garages need rebar and bolts, adding structural stability and cost.
- Permit and inspection fees: Some areas require foundation inspections or zoning permits, increasing total expenses.