Deck Construction cost in Portsmouth, NH
Portsmouth, NH · updated August 2026
$12,400
Typical local cost
$5,900 – $30,200
Typical range
- per sq ft of deck
- $32.50 – $81
- Permit
- Yes
- Typical timeline
- 1-2 weeks of work
Installed, local pricing
$105 – $420 in fees
1-2 weeks of work, 3-6 weeks including permitting
Portsmouth runs +8% against the U.S. average · data confidence High · modeled estimate, not a quote
Most Portsmouth homeowners pay around $12,400. The local adjustment for this trade is x1.078 — driven mainly by Rockingham County labor rates and 55% exposure to local code requirements.
Estimate your Portsmouth job
Priced with this market's cost index, so the calculator, the size table and the ranges on this page all agree.
Deck area
320 sq ft
- Decking (linear feet)
- 696 lf
- 16 ft boards needed
- 44 boards
- Joists
- 16 at 16" o.c.
- Footings
- 8
- Installed cost estimate
- $13,464 – $21,384
Estimates only. Local pricing, site conditions and code requirements change the real number.
Cost by project size
Generated from the same unit pricing the calculator uses.
| Project size | Estimated range |
|---|---|
| 125 sq ft of deck | $4,100 – $10,100 |
| 175 sq ft of deck | $5,700 – $14,200 |
| 225 sq ft of deck | $7,300 – $18,200 |
| 275 sq ft of deck | $8,900 – $22,300 |
| 375 sq ft of deck | $12,200 – $30,400 |
Based on Portsmouth pricing of $33–$81 per sq ft of deck.
Cost by material
Installed cost in this market, with expected service life.
| Material | Installed range | Lifespan | Maintenance |
|---|---|---|---|
| Composite Decking | $14,300 – $23,600 | 25–35 yrs | Very low |
| Pressure-Treated Decking | $7,200 – $11,800 | 10–20 yrs | High |
Where the money goes
- Labor
- $7,200
- 57% of median
- Materials
- $5,200
- 41% of median
- Permit & fees
- $265
- 2% of median
Portsmouth project costs+8% vs U.S. average
Based on Rockingham County labor rates, local material logistics and permit-fee posture for this trade.
What the project looks like start to finish
Typical sequence for this scope. Timing varies with contractor backlog and plan-review queues.
01
Planning & quotes
Scope, material choice, contractor selection
02
Permit application
Filed with City of Portsmouth building department
03
Materials & staging
Order lead time on non-stock materials
04
Installation
1-2 weeks of work, 3-6 weeks including permitting
05
Inspection
Footing inspection, Framing inspection, Final inspection
06
Closeout
Final sign-off, warranty and documentation
Portsmouth labor intelligence
What the trade charges here, and how much of your price it is.
Loaded hourly rate
$60–$77
Outdoor crews in Rockingham County · +9% vs U.S. ($62/hr)
Typical crew
3 × 4.5 days
On-site time for a typical deck job here.
Labor in the price
$7,200
58% of the median — the rest is material, disposal and permit.
Because labor is 58% of this job, Portsmouth wage levels move the price far more than material prices do. A quote well under this labor figure usually means a smaller crew, a longer schedule, or unlicensed help.
Basis: Hometriva labor model: national outdoor crew rates adjusted by the Rockingham County labor factor (x1.091). · BLS Occupational Employment and Wage Statistics, Hometriva methodology
Why Portsmouth differs from the national average
The local delta, broken into dollars by driver.
Trade labor rates+$600
Rockingham County crews price 9% above the national average, and labor is 58% of this job.
Material and delivery+$275
Materials are nationally traded, so they move less — but delivery into this market runs 5% over baseline.
Permit fees-$25
Fees are paid to the jurisdiction, not the contractor, and are budgeted separately from the contract price.
Code and inspection load+$25
Deck Construction carries 55% exposure to local code requirements, and this jurisdiction's review load indexes at x1.00.
Basis: Decomposition of the modeled Portsmouth median against the U.S. median for this scope. · City of Portsmouth building department, Hometriva methodology
Portsmouth vs New Hampshire vs the U.S.
Change the inputs, see your number
The same local model, run against your job instead of the average one.
Simulated deck construction in Portsmouth
$12,665
Likely range $6,165 – $30,465
Simulated from the same local model as the numbers above — it changes the inputs, not the pricing method.
What makes the number move
- Deck square footage and height above grade
- Material: pressure-treated pine, composite or hardwood
- Footings and uplift hardware
- Railings and stairs
- Attachment to the house versus freestanding
Who issues each permit
Tracked per discipline — the building permit issuer is not always the body that reviews electrical, plumbing, zoning or fire.
| Discipline | Issuing authority |
|---|---|
| building | City of Portsmouth building departmentModeled estimate |
| electrical | City of Portsmouth building departmentModeled estimate |
| mechanical | City of Portsmouth building departmentModeled estimate |
| plumbing | City of Portsmouth building departmentModeled estimate |
| zoning | City of Portsmouth building departmentModeled estimate |
| fire | City of Portsmouth building departmentModeled estimate |
Permit requirement in Portsmouth
Yes — a permit is required for deck construction in Portsmouth, NH. The work must be inspected before it can be closed out, and a homeowner may be able to pull an owner-builder permit on a home they own and occupy.
- Permitting authority
- City of Portsmouth building departmentModeled estimate
- Permit fee
- Estimated allowance $105–$420Modeled from comparable fee schedules — not an official quoted fee.
Inspections
- Footing inspection
- Framing inspection
- Final inspection
Local conditions that change this job
Only the exposures that materially affect deck construction.
Humidity
Severe84/100
Annual rainfall
High74/100
Coastal / salt-air exposure
Moderate45/100
Portsmouth sits in Rockingham County, New Hampshire. Deep frost lines, snow load and a very old housing stock mean permits frequently touch structural, electrical and energy-code upgrades at once. Work outside city limits is permitted by the county building department rather than the city.
Nearby market comparison
| Market | Local factor | Median | Per sq ft of deck |
|---|---|---|---|
| Portsmouth (this page) | x1.078 | $12,400 | $32.50 – $81 |
| Manchester | x1.117 | $12,800 | $33.50 – $84 |
| Nashua | x1.117 | $12,800 | $33.50 – $84 |
| Concord | x1.078 | $12,400 | $32.50 – $81 |
What Portsmouth homeowners actually paid
Real reported invoices from this market, aggregated. Add yours — it takes 20 seconds and no personal details.
Quotes homeowners were given in Portsmouth
Quotes run ahead of final invoices. Reporting yours shows the local spread and where there is room to negotiate.
How Hometriva estimates Portsmouth deck costs
Hometriva does not publish invented city prices. The Portsmouth estimate for deck construction is produced by this chain, and every input is stored separately:
- National baseline$11,500
Typical U.S. cost for deck construction on a single-family home.
- Local labor factorx1.091
Portsmouth-area trade labor rates, weighted at 58% of this job.
- Material factorx1.055
Material and delivery pricing into Rockingham County, weighted at 42%.
- Regulatory factorx1.004
Local code, product-approval and inspection load, applied at 55% for this project type.
- Applied multiplierx1.078
Blended Portsmouth adjustment specific to deck construction.
- Permit component$105 – $420
Budgeted separately from the contract price because it is paid to the jurisdiction.
Because labor, material and regulatory factors are weighted per project, deck construction in Portsmouth carries a different local adjustment than other trades in the same market.
Reviewed by
Hometriva Cost Data Desk
Maintains the unit-cost baselines, local adjustment factors and material pricing. Reviewed for deck construction pricing in Portsmouth, NH.
- • National unit-cost baselines against current trade pricing
- • Local labor and materials factors for the market
- • Material installed-cost ranges and service life
Last reviewed August 2026 · Editorial standards · Report an error
Frequently asked questions
Do I need a permit to build a deck?
Most Florida jurisdictions require a permit for any deck attached to the house or elevated above a set height (commonly 12-30 inches). Ground-level floating decks under that threshold are sometimes exempt.
Sources
Sources & verification
Last verified August 2026. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing — they are not quotes. Permit rules change; confirm with the building department before starting work.