A 20x20 pergola typically costs between $3,000 and $15,000 for a DIY aluminum kit, while professionally installed custom louvered pergolas covering 400 square feet run $20,000 to $40,000 or more.
The price spread comes down to three variables: materials (wood versus powder-coated aluminum versus vinyl), roof type (open lattice versus adjustable louvered versus solid), and whether installation labor is included. A 20x20 aluminum louvered pergola kit — the same adjustable-roof format that contractors charge $27,000+ to build custom — sits in the $3,500 to $8,000 range from direct-to-consumer brands. Add permits, anchoring hardware, and professional assembly and the total can push toward $12,000 to $15,000.
- DIY aluminum louvered pergola kits for a 20x20 footprint: $3,500–$8,000 before installation.
- Custom professionally installed louvered pergolas at 400 sq ft: $20,000–$40,000+ depending on region and materials.
- A 20x20 pergola covers 400 square feet — enough for a full dining set, conversation set, and grill station side-by-side.
- Wood pergola kits (cedar or pressure-treated) at 20x20 typically range from $2,500 to $6,000 for materials alone.
- Permit costs for a permanent pergola structure: $100–$1,000 depending on local municipality requirements.