Deck Build Cost Calculator

Typical 16×20 ft deck material cost ranges: pressure-treated wood $4,800-$8,000, cedar $6,400-$9,600, composite (Trex/TimberTech) $9,600-$16,000, IPE/tropical hardwood $17,600-$22,400. Labor runs 60-70% of materials, and the substructure, railing, and any stairs are additional costs on top of the decking material itself - the calculator above already totals all of these together, so its output for the same size deck runs higher than the material-only figures here. Adding stairs adds $1,500-$3,000 each; railing adds $25-$50/linear ft. Decks over 30" off the ground typically require permits and engineered footings, adding $1,000-$3,000.

Composite (Trex, TimberTech, Fiberon) costs 2-3× pressure-treated upfront but lasts 30+ years with zero maintenance vs PT's 20-year life requiring annual cleaning + biennial staining. Lifetime cost is similar or composite wins, but you pay the difference upfront. Best fit for composite: humid climates, heavy UV exposure, busy households. PT still wins for budget projects or detached decks with limited use.

Most jurisdictions require a permit for decks over 30" off the ground OR over 200 sq ft OR attached to the house. Ground-level freestanding patios under 200 sq ft often don't require permits. Always check local code - unpermitted decks become serious liability at resale and can void homeowners insurance claims. Permit costs: $200-$800 typical; HOA approval separate.

Composite requires tighter joist spacing - 12" on-center vs 16" for wood - because composite is more flexible. Most manufacturers also require hidden fasteners (no visible screws), specific board spacing for thermal expansion, and ventilation under the deck. Skip these and the warranty is voided. Substructure cost is 15-25% higher than wood as a result.

A 200 to 400 sq ft deck takes 1 to 3 weeks with an experienced crew, including footings, framing, decking, railing, and stairs. DIY it and plan for 4 to 8 weekends.