Key takeaways
- A 20×20 deck is 400 square feet. At 2026 published installed prices that is about $10,000 to $20,000 in pressure-treated pine and $14,000 to $32,000 in composite or PVC.
- The permit is a known cost. Gloucester Township’s code sets a flat $150 fee for a deck of 201 to 400 square feet.
- Twenty feet deep changes the frame. It is past the longest single joist span in the standard deck guide, so the deck needs a second beam or a cantilever.
- Railing and stairs swing the total. A deck attached on one side has 60 feet of open edge.
A 20×20 deck in Camden County, NJ should cost roughly $10,000 to $20,000 in pressure-treated pine and $14,000 to $32,000 in composite or PVC, installed, at 2026 published prices. That is 400 square feet of deck, and the spread comes from the board you choose, how high the deck sits, and how much railing and stair work it needs. The figures below come from dated national price guides and from Camden County township fee schedules, so you can check each one.
20×20 deck cost by material
Material is the biggest single driver: premium composite starts at the price where pressure-treated pine tops out. The table multiplies each published 2026 installed price per square foot by 400.
| Decking material | Installed, per sq ft | 20×20 deck (400 sq ft) | Published by |
|---|---|---|---|
| Pressure-treated pine | $25 to $50 | $10,000 to $20,000 | HomeGuide, Feb. 2026 |
| Cedar | $30 to $47 | $12,000 to $18,800 | HomeGuide, Feb. 2026 |
| Mid-range composite | $35 to $55 | $14,000 to $22,000 | Ergeon, May 2026 |
| Premium composite | $50 to $70 | $20,000 to $28,000 | Ergeon, May 2026 |
| PVC | $55 to $80 | $22,000 to $32,000 | Ergeon, May 2026 |
Sources: HomeGuide and Ergeon. Angi put a 20×20 deck at $16,000 to $24,000 in September 2026. These are national ranges, not our quote.
Regional data runs higher. The 2025 Cost vs. Value report for the Middle Atlantic region, which includes New Jersey, priced a smaller 16×20 wood deck at $22,717 and the composite version at $28,209. Those projects include stairs and a full railing system, which is the difference between a per-square-foot figure for decking and the price of a finished deck. For help choosing a board, see our composite decking in Camden County and South Jersey page.
What the permit adds in Camden County
The permit on a 20×20 deck in Camden County costs from about $150 to more than $800 depending on the town, because each municipality sets its own fee schedule. Some charge a flat fee by deck size and others charge a rate per $1,000 of job cost.
| Town | Published fee basis | On a $20,000, 400 sq ft deck |
|---|---|---|
| Gloucester Township | Flat fee by size: $150 for 201 to 400 sq ft | $150 |
| Voorhees | $40 per $1,000 of cost, $75 minimum, plus a $60 zoning permit | $800 plus $60 |
| Pennsauken | $40.80 per $1,000 of cost, $75 minimum | $816 |
| Cherry Hill | $34 per $1,000 at the alteration rate, $65 minimum, plus a $50 zoning permit | $680 plus $50 |
Calculated from each town’s published rate, checked October 2026. State surcharges and any electrical permit are extra, so confirm the total with the construction office. Sources: Gloucester Township code, Voorhees, Pennsauken code, Cherry Hill.
We pull the permits and schedule the inspections on every deck we build. The state rules and the offices for 21 towns are in our NJ deck permit guide.
What goes into a 20×20 deck
A 20×20 deck uses about 860 linear feet of decking, 16 joists and up to 60 feet of railing, and its 20-foot depth forces a framing decision that smaller decks avoid. Knowing the quantities makes it easier to compare quotes line by line.
- Decking: 43 rows of 5.5-inch boards across a 20-foot width, about 860 linear feet. That is 48 twenty-foot boards with 10 percent for waste.
- Joists: 16 joists at 16 inches on center, the maximum spacing composite manufacturers allow. A diagonal pattern needs 12-inch spacing, which is 21 joists.
- Beams and footings: the longest joist span in the American Wood Council’s DCA 6 deck guide is 18 feet. A deck that projects 20 feet from the house needs a cantilever past the beam or a second beam line with its own footings.
- Railing: a deck attached along one 20-foot side has 60 feet of open edge. A guard is required only where the surface is more than 30 inches above the ground.
What moves a 20×20 deck price up or down
Four things move the total more than the board brand does: height, railing, stairs and what has to be removed first. Two 400-square-foot decks in the same Camden County town can differ by thousands of dollars on these items alone.
| Item | Published national range | On a 20×20 deck |
|---|---|---|
| Composite railing | $15 to $60 per linear ft | $900 to $3,600 for 60 ft |
| Aluminum railing | $50 to $200 per linear ft | $3,000 to $12,000 for 60 ft |
| Demolition of an old deck | $5 to $15 per sq ft | $2,000 to $6,000 for 400 sq ft |
Ranges from Angi’s 2026 cost guides. National figures, not a quote.
A deck low enough to need no guard skips most of the railing line entirely, and a second-story deck adds taller posts, bracing and a full stair run. If an old deck is coming out first, our deck replacement and resurfacing page explains when the existing frame can be reused. The wider budget picture is in our South Jersey deck cost guide, and financing is available.
20×20 deck cost questions
How much does a 20×20 composite deck cost?
At 2026 published installed prices, a 20×20 composite deck costs about $14,000 to $22,000 with mid-range boards and $20,000 to $28,000 with premium boards. PVC decking runs $22,000 to $32,000 for the same 400 square feet. Height, stairs and railing length move the number more than the brand does.
How much does a 20×20 pressure-treated deck cost?
About $10,000 to $20,000 installed, based on the $25 to $50 per square foot range HomeGuide published in February 2026. Pressure-treated pine is the lowest-cost surface, and it needs cleaning and re-sealing on a regular cycle to last in New Jersey weather.
How many deck boards do I need for a 20×20 deck?
Forty-three rows of 5.5-inch boards cover a 20-foot width, which is about 860 linear feet of decking. Using 20-foot boards, order 48 to allow 10 percent for waste and cuts. A picture-frame border or a diagonal pattern adds to that.
How many footings does a 20×20 deck need?
There is no fixed number. Each post gets a footing, and post spacing is set by the beam size in the approved plan. A deck that projects 20 feet from the house is longer than the 18-foot maximum joist span in the American Wood Council’s DCA 6 guide, so it needs a second beam line or a cantilever, and a second beam means a second row of footings.
Do I need a permit for a 20×20 deck in Camden County, NJ?
Yes. New Jersey requires a construction permit for any new deck, and Camden County towns add a zoning permit before it. In Gloucester Township a 20×20 deck falls in the 201 to 400 square foot bracket, which the township code prices at a flat $150. Our NJ deck permit guide lists the other towns.
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Garden State Decks LLC, 141 Ganttown Rd, Suite D-1, Blackwood, NJ 08012. Find us on Google Maps.
