Cost to Build a 16x20 Deck: 2026 Material and Labor Guide
Estimate the cost to build a 16x20 deck in 2026. Compare pressure-treated wood, cedar, composite decking, railing, stairs, labor, and permit costs.
How Much Does a 16x20 Deck Cost?
A 16x20 deck is 320 square feet. In 2026, a typical installed 16x20 deck costs $8,000 to $24,000, depending on decking material, deck height, railing, stairs, footings, and local labor rates.
Use the Deck Building Cost Calculator to adjust the deck size, cost per square foot, railing option, and stair option for your project.
16x20 Deck Cost by Material
| Deck material | Typical installed cost | Best for |
|---|---|---|
| Pressure-treated wood | $8,000 - $14,000 | Lower upfront budget |
| Cedar | $11,000 - $18,000 | Natural wood look |
| Composite | $15,000 - $28,000 | Lower maintenance |
| PVC or premium composite | $20,000 - $34,000 | Long-term durability |
| Hardwood | $22,000 - $38,000 | Premium outdoor finish |
Pressure-treated wood is usually the cheapest way to build a 16x20 deck, but it needs sealing, staining, and board replacement over time. Composite costs more upfront, but it reduces long-term maintenance.
Cost Breakdown for a 320 Sq Ft Deck
| Line item | Typical cost |
|---|---|
| Deck boards | $2,400 - $8,000 |
| Joists, beams, posts, and framing | $1,500 - $4,000 |
| Concrete footings | $400 - $1,200 |
| Fasteners and hardware | $300 - $900 |
| Basic railing | $1,200 - $3,500 |
| One stair set | $600 - $1,800 |
| Labor | $4,000 - $12,000 |
| Permit and inspection | $150 - $800 |
What Makes a 16x20 Deck More Expensive?
The biggest cost drivers are height, material, railing, stairs, and site conditions. A low rectangular deck with wood boards is much cheaper than an elevated composite deck with custom railing and wide stairs.
If the deck is more than 30 inches above grade, many cities require guards, stairs, deeper footings, and a more detailed permit review. Sloped yards also raise labor because posts, beams, and bracing become more complex.
DIY vs. Contractor
DIY can save several thousand dollars on labor, but a 320 sq ft deck is not a small weekend project. It may require layout work, ledger attachment, post setting, joist framing, stair math, and inspections.
DIY is more realistic for a low, freestanding deck. Hire a contractor for elevated decks, second-story decks, complex stairs, ledger attachment to the house, or composite systems with manufacturer warranty requirements.
Quick Planning Tips
- Check local permit rules before buying materials.
- Price railing separately; it can be a major budget item.
- Compare wood and composite over a 10- to 20-year ownership period.
- Ask contractors whether demo, hauling, permit handling, and stairs are included.
- Use the 12x12 deck scenario if you want to compare a smaller baseline first.
FAQ
Is a 16x20 deck big enough for dining and seating?
Yes. A 320 sq ft deck is large enough for a dining set, grill area, and small lounge zone if the layout is planned carefully.
What is the cheapest 16x20 deck material?
Pressure-treated wood is usually the lowest upfront cost. The tradeoff is ongoing maintenance.
Should I choose composite for a 16x20 deck?
Composite makes sense if you want lower maintenance and plan to stay in the home for years. For a short-term budget project, wood may be more practical.
*Estimates are U.S. planning ranges as of July 2026. Local quotes can vary based on labor, access, permitting, and material availability.*