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How much does a new deck cost in Portsmouth, NH?

Regionally adjustedUpdated Prices checked October 20262 sources

In Portsmouth, a new deck typically runs $4,890 to $14,270, about $9,390 for a typical job. That is the US national range from HomeAdvisor ($4,338 to $12,653) adjusted by the New England factor of 1.13 from the 2025 Cost vs. Value Report. Checked October 2026.

Adjusted for the New England region

Low
$4,890
Typical
$9,390
High
$14,270

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Deck building cost in Portsmouth, NH

Each row says exactly what the figures are and where they come from.

Deck building cost in Portsmouth, NH
EstimateLowTypicalHighBasisChecked
New England estimate$4,890$9,390$14,270National range × 1.13: the New England / national cost ratio for “Deck Addition | Wood” ($20,603 vs $18,263) in the 2025 Cost vs. Value ReportOctober 2026
US national range$4,338$8,321$12,653Per deck: typical range of customer-reported projects (HomeAdvisor)October 2026

Deck building cost by type or size

US national figures in USD, as published by each source.

Deck building cost by type or size
Type or sizePrice (USD)Source
10 × 10 ft (100 sq ft)$4,000 to $6,000HomeAdvisor
20 × 20 ft (400 sq ft)$16,000 to $24,000HomeAdvisor

What drives the cost of a new deck

  1. Size and height

    Second-story and multi-level decks need more structure.

  2. Decking material

    Pressure-treated wood runs $2 to $5 per sq ft; composite $12 to $22.

  3. Labor

    Labor runs $15 to $35 per sq ft.

  4. Railings and stairs

    Railings cost $35 to $210 per linear foot.

  5. Old deck removal

    Demolition runs $5 to $15 per sq ft.

  6. Season

    Off-season work can be up to 20% cheaper.

Permits and what's included in Portsmouth

Permit note

Most places require a deck permit, typically $230 to $500 depending on location, size and height.

Rules are set locally; confirm with Portsmouth’s building department.

What’s usually included

  • Footings and framing
  • Decking boards
  • Railings and stairs in the agreed design
  • Installation labor

Scopes vary. Get the scope in writing on every quote.

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Top-ranked deck builders in Portsmouth

The top 3 of 37 deck builders we rank for Portsmouth, NH, by CR Score. Paid placement never changes rank.

  1. #1
    Northeast Walls and Patios
    CR Score 635.0from 126 Google reviews
  2. #2
    Shoreline Hardscapes & Construction, LLC
    CR Score 544.7from 26 Google reviews
  3. #3
    Premium Deck Restoration LLC
    CR Score 544.8from 16 Google reviews

See all ranked deck builders in Portsmouth

Deck building cost in Portsmouth: questions

How much does a new deck cost in Portsmouth, NH?

In Portsmouth, a new deck typically runs $4,890 to $14,270, about $9,390 for a typical job. That is the US national range from HomeAdvisor ($4,338 to $12,653) adjusted by the New England factor of 1.13 from the 2025 Cost vs. Value Report. Checked October 2026.

Why is the Portsmouth price different from the national price?

The 2025 Cost vs. Value Report puts the “Deck Addition | Wood” project at $20,603 in the New England division against $18,263 nationally, a factor of 1.13. We apply that factor to the national range. It is a division-level adjustment, not a Portsmouth price survey.

Do I need a permit for a new deck in Portsmouth?

Most places require a deck permit, typically $230 to $500 depending on location, size and height. Rules are set locally, so confirm with Portsmouth’s building department.

What affects the cost of a new deck?

Size and height: second-story and multi-level decks need more structure. Decking material: pressure-treated wood runs $2 to $5 per sq ft; composite $12 to $22. Labor: labor runs $15 to $35 per sq ft. Railings and stairs: railings cost $35 to $210 per linear foot.

How many deck builders serve Portsmouth?

We rank 37 deck builders for Portsmouth, NH by CR Score. Get at least three written quotes for the same scope.

What is usually included in the price?

Footings and framing; Decking boards; Railings and stairs in the agreed design; Installation labor. Always get the scope in writing on the quote.

Sources

Checked October 2026. Figures are estimates, not quotes.

  1. HomeAdvisor: Deck building cost · page updated June 17, 2026 · checked October 2026Primary source. Used for: Low, typical and high; prices by size; drivers; permit.
  2. Journal of Light Construction: 2025 Cost vs. Value Report: Deck Addition, Wood · page updated 2025 · checked October 2026Used for: Regional adjustment ratio.
  3. Journal of Light Construction: 2025 Cost vs. Value Report, New England division · checked October 2026Used for: Regional factor 1.13 for “Deck Addition | Wood”.
These are published estimates with a documented regional adjustment, checked October 2026. They are not quotes. Typical range shown: $4,890 to $14,270. Editorial policy

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