If the custom-built option is the way you’d like to go, and you’re not well-versed in building, well, anything yourself, hiring a contractor might be your best option. The national average cost of a pergola by size: • 10 feet x 10 feet: $3,000 - $6,000 • 11 feet x 11 feet: $3,630 - $7,260 • 12 feet x 12 feet: $4,320 - $8,640 • 10 feet x 14 feet: $4,200 - $8,400 • 12 feet x 18 feet: $6,480 - $12,960 • 10 feet x 20 feet: $6,000 - $12,000 If you intend to hire a contractor, add an additional $20 to $60 per hour for manual labor. Don’t let the prices deter you.