How much does it cost to build a deck?
Building a new deck often costs $25 - $50 per square foot for many wood or basic composite projects. A 12x12 deck may cost around $3,600 - $7,200, while a 20x20 deck can reach $10,000 - $20,000+.
Deck quotes change quickly with material, height, stairs, railings, footings, demo, permits, lighting, privacy screens, drainage, and whether the old deck must be removed.
Deck cost by project type
Basic pressure-treated wood deck
$25 - $50/sq ftHow to tellSimple rectangular layout, low height, standard stairs/railing
The fixBuild frame, footings, decking, stairs, and basic railings
Composite deck
$40 - $80+/sq ftHow to tellLow-maintenance boards, hidden fasteners, upgraded railing
The fixBuild compatible frame and install composite decking system
Elevated or second-story deck
$50 - $100+/sq ftHow to tellTall posts, stairs, landings, engineered footings, guardrails
The fixMore structural work, access labor, and permit scrutiny
Old deck demolition
$5 - $15+/sq ft add-onHow to tellExisting deck must be removed before replacement
The fixDemo, haul away, inspect ledger, and rebuild
Railings, stairs, lighting, and features
$1,000 - $15,000+ add-onHow to tellCable railing, privacy wall, built-in benches, lighting, pergola
The fixAdd specialty materials and finish carpentry
Before planning a deck
- Measure the desired deck size and note height above grade, number of stairs, and railing length.
- Ask whether permits, drawings, footings, ledger flashing, and inspections are included.
- Compare wood vs composite using total ownership cost, not just the initial quote.
- Ask how the contractor handles hidden rot where the deck attaches to the house.
Unlock the hiring checklist
Use this before you call a deck builder, so you know what to ask and what to avoid.
Call a pro when…
- The deck attaches to the house or is more than a small ground-level platform
- Railings, stairs, footings, or permits are required
- The old deck has rot or structural concerns
- You want composite materials or manufacturer warranty coverage
- The project changes doors, patios, grading, drainage, or landscaping
Repair or replace?
Build new when you want a different layout, the frame is unsafe, posts/joists/ledger are failing, or the old deck cannot meet code. Repair makes sense when the frame is sound and only boards, rails, stairs, or hardware need targeted replacement.
Need a cleaner scope before you call around?
Use the decks checklist to compare the same work, questions, cleanup, and warranty before choosing a local company.
Related questions
Is composite decking worth the extra cost?
Composite costs more upfront but reduces staining, sealing, splinters, and maintenance. It is often worth comparing if you plan to keep the home for years.
Do I need a permit to build a deck?
Many decks require permits, especially if attached to the house, elevated, or built with stairs and railings. Local rules vary, so verify before work starts.
What should a deck quote include?
It should include size, materials, frame specs, footing details, railing/stair scope, permits, demo, disposal, warranty, and any exclusions.