Cost to Build a 16x20 Deck in 2026: Wood, Composite, Labor
Cost to build a 16x20 deck in 2026. Compare wood, cedar, composite, railing, stairs, footings, permits, labor, DIY, and contractor pricing.
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.
Quick answer: a ground-level pressure-treated 16x20 deck often lands near $8,000-$14,000 installed. A composite 16x20 deck with railing and stairs often lands around $15,000-$28,000+. Elevated decks, complex stairs, premium railing, and difficult footings can push the total higher.
16x20 Deck Cost at a Glance
| Scope | Typical 2026 Cost |
|---|---|
| DIY pressure-treated wood materials | $4,000-$8,000 |
| Contractor-built pressure-treated deck | $8,000-$14,000 |
| Cedar 16x20 deck | $11,000-$18,000 |
| Composite 16x20 deck | $15,000-$28,000 |
| Premium composite or PVC deck | $20,000-$34,000+ |
| Elevated deck with stairs and railings | $18,000-$38,000+ |
The biggest difference is not only deck size. Height, railing, stair count, ledger attachment, footing depth, permits, and material choice can change the quote as much as the square footage.
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 per Square Foot for a 16x20 Deck
Because a 16x20 deck is 320 sq ft, each $10 per sq ft change adds $3,200 to the project. That is why material and labor assumptions matter so much.
| Cost per Sq Ft | 16x20 Total |
|---|---|
| $25 per sq ft | $8,000 |
| $35 per sq ft | $11,200 |
| $50 per sq ft | $16,000 |
| $65 per sq ft | $20,800 |
| $85 per sq ft | $27,200 |
A low, simple wood deck may price near the lower rows. A composite deck with rails, stairs, and permitted structural work often moves into the middle or upper rows.
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 |
Ask contractors to separate boards, framing, railing, stairs, footings, permit handling, and demolition. A single lump-sum number is hard to compare because one bid may include railing and stairs while another does not.
Railing and Stair Cost
Railing and stairs are the fastest way for a 16x20 deck to get more expensive.
| Add-On | Typical Added Cost |
|---|---|
| Wood railing | $30-$80 per linear ft |
| Composite or aluminum railing | $60-$150 per linear ft |
| One basic stair run | $600-$1,800 |
| Wide stairs or landing | $1,500-$4,000+ |
| Elevated guardrail requirements | Varies by height and code |
If the deck is close to the ground, you may need little or no railing depending on local code. If it is elevated, railing and stairs become structural and safety items, not decorative extras.
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.
Permit and Code Notes
Many cities require permits for decks over a certain height, size, or attachment type. Decks attached to the home usually face stricter review than small freestanding platforms.
Before you price materials, confirm:
- Whether a permit is required.
- Footing depth and frost-line rules.
- Ledger board attachment requirements.
- Guardrail and stair requirements.
- Setbacks from property lines.
- HOA rules for material, color, and railing style.
Skipping the permit can create resale, insurance, and removal problems. For a 320 sq ft deck, it is better to assume permitting may apply until your local building office says otherwise.
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.
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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.
How many square feet is a 16x20 deck?
A 16x20 deck is 320 square feet. Multiply the installed cost per square foot by 320 to create a fast planning estimate.
Is a 16x20 deck a DIY project?
It can be DIY for an experienced homeowner if the deck is low and freestanding. Hire a contractor for elevated decks, house-attached ledgers, complex stairs, or any design that requires engineered details.
*Estimates are U.S. planning ranges as of July 2026. Local quotes can vary based on labor, access, permitting, and material availability.*