Shed pricing splits into three categories: factory-prefab delivered assembled ($1,500-$8,000 for 6x8 to 12x16), DIY kit assembled on site ($3,000-$12,000), and custom site-built ($5,000-$25,000+). Per sq ft construction cost: prefab $35-$65, kit $50-$80, custom $80-$150, high-end custom (matching house style with full insulation and electrical) $150-$300.
Foundation options — match to shed size and use
4x6 to 6x8 sheds: gravel pad (4 inches of compacted 3/4-inch stone over 24 inches of base) works fine, $100-$300 in materials. 8x10 to 12x12: concrete piers or skid foundation ($300-$800). 12x16 and up: concrete slab foundation ($600-$2,500) for long-term stability and resale value. Foundations below frost line are only needed for any shed that connects to a permanent structure or requires a permit — most accessory sheds can sit on frost-tolerant gravel or pier foundations.
When do sheds need permits
Permit thresholds vary enormously. Generally, sheds under 100-200 sq ft and under 10-12 feet tall don't require permits in most jurisdictions. Larger sheds, sheds with electrical, sheds on permanent foundations, and sheds with plumbing always require permits. HOAs frequently have separate rules. Check before buying — an unpermitted shed discovered during home sale can force removal or retroactive permitting.
Prefab vs site-built decision
Prefab shed (Tuff Shed, Lifetime, Heartland): cheapest for small sizes, delivered fully assembled, 10-25 year warranties, limited customization. Site-built from kit (Home Depot, Amish builders): better quality than big-box prefab, allows more customization, takes 2-3 weekends of DIY labor. Custom site-built by contractor: highest quality, matches house architecture, 30+ year lifespan, 2-4x prefab price. For pure storage, prefab is usually the right call; for sheds that add curb appeal or will be converted to ADUs later, custom construction pays back.