Decks
How Much Does a New Deck Cost on Cape Cod and the South Shore?
A new deck in southeastern Massachusetts usually costs in the tens of thousands of dollars, not the few thousand a lumber list suggests. The most recent public benchmark, the 2025 Cost vs. Value report, puts a 16-by-20-foot composite deck at $25,817 in New England and the same deck in pressure-treated wood at $20,603. Here is what those numbers include and what changes them on Cape Cod and the South Shore.
Key points
- The 2025 Cost vs. Value report puts a 16-by-20-foot composite deck at $25,817 in New England and the same deck in pressure-treated wood at $20,603.
- That is roughly $81 per square foot for composite and $64 for wood, for a simple deck a few steps off the ground.
- Height, stairs, railings, the site, and tearing out an old deck move the price more than the boards do.
- Permits, footings below the frost line, and wetland or historic reviews are part of the cost in many towns.
What the benchmark deck includes
The report prices the same 16-by-20-foot deck, 320 square feet, in every region, with a railing and a short set of stairs. The composite version uses composite boards and railing; the wood version uses pressure-treated lumber.
The per-square-foot figures divide the job cost by those 320 square feet. Use them as a rough guide, not as a quote.
| Deck | New England | U.S. average | Per sq ft, New England |
|---|---|---|---|
| Composite | $25,817 | $25,096 | about $81 |
| Pressure-treated wood | $20,603 | $18,263 | about $64 |
What makes a deck cost more or less
The boards are only part of the price. These move it the most:
- Size and shape: every corner, angle, and extra level adds framing and labor.
- Height off the ground: taller posts, bracing, and longer stair runs.
- Stairs and landings: each run of stairs is its own small structure.
- Railings: composite, PVC, wood, and cable railings all price differently, and they run along every open edge.
- The site: sandy soil, slopes, and tight access change the footings and the labor.
- Tearing out an old deck: removal and disposal come before anything new goes up.
- Salt air: stainless or coated connectors and fasteners cost more than standard ones near the water, and they are worth it.
How to ballpark your deck
Multiply the deck area by about $64 per square foot for pressure-treated wood or about $81 for composite, based on the New England benchmark. Then add for anything the benchmark does not have, like more height, more stairs, a premium railing, or a tear-out.
A 12-by-16-foot composite deck, 192 square feet, works out to roughly $15,500 at the benchmark rate before any extras. The number to plan around is a written estimate after someone has seen your house and your yard.
Permits and approvals belong in the budget
A new deck needs a building permit, with footings set below the frost line the Massachusetts building code requires. Near wetlands, beaches, and pond banks the town Conservation Commission reviews it, and in historic districts, like the Old King’s Highway district along Route 6A on the Cape, a deck that can be seen from the road needs approval too.
Is a deck worth what it costs?
In the same 2025 report, a composite deck in New England recovered 95.8 percent of its cost at resale and a wood deck 79.1 percent. Around here a deck also gets used from spring through fall, which is the part resale numbers leave out.
Frequently asked questions
What is the least expensive way to build a deck?
A simple rectangle, low to the ground, in pressure-treated wood, with a basic railing and few stairs. Every corner, level, and step adds cost.
Is composite worth the extra cost?
Often, yes. Composite does not need sanding or staining, and in the 2025 report a composite deck recovered more of its cost at resale in New England (95.8 percent) than a wood deck (79.1 percent).
Does replacing a deck cost the same as building a new one?
Close to it, plus the tear-out. If the old frame and footings are rotted or undersized, the new deck is built from the ground up.
Planning a new deck?
Cedar House Carpentry handles decks across Cape Cod and the South Shore with our own in-house crew, fully licensed and insured.