A deck is priced by footprint, height and material, but ground conditions and code requirements can change the structure below the boards more than the boards themselves.
What the permit filings show
Based on 3,474 residential building-permit filings. The median deck / decking build valuation runs from $14,433 in Austin to $30,000 in Seattle, about 2.1× the cheapest city. Within a city the spread matters too: the middle half of Seattle filings spans 293% of its median, versus 75% in Chicago.
CityTypical range (P25–P75)MedianFilings
Austin$6,110 – $40,000$14,433184
San Francisco$6,550 – $45,000$15,0001,095
Chicago$12,000 – $30,000$24,025229
Seattle$12,000 – $100,000$30,0001,966
Filings are declared valuations from each city's open permit dataset, limited to residential records classified as deck / decking build work and valued between $1,000 and $2,000,000. A city is listed only when at least 30 filings qualify. Full methodology. Data refreshed September 2026.
What the numbers say
Sample size varies by city too — 1,966 qualifying deck / decking build filings back the Seattle figures above, versus just 184 for Austin — and while both clear the site's 30-filing minimum, Seattle's far larger sample settles into a steadier shape than Austin's, which sits closer to that threshold.
Zoom out across every city on this page and the legitimate range is wider still: the lowest 25th-percentile figure is $6,110, in Austin, and the highest 75th-percentile figure is $100,000, in Seattle — a 16.4× gap that reflects different cities, codes and building stock, not overcharging.
In Chicago, quotes cluster tightly: the middle half of filings sits between $12,000 and $30,000, so a quote near the $24,025 median there is the safer assumption. In Seattle, that band runs from $12,000 to $100,000 — wide enough that a quote toward either edge is still plausible, so treat Seattle's median as a starting point for a conversation, not a target.
Structure comes first
Footings, framing and connections to the house are the parts you never see and the parts inspectors care about most. A higher deck needs stronger supports and railings that meet code, and difficult soil can change footing depth and cost.
Surface and maintenance
Pressure-treated lumber is the lower-cost option with regular upkeep; composite and hardwood decking cost more up front and trade maintenance for price. Compare lifetime cost rather than only the installed figure.
Permits and inspections
Most jurisdictions require permits for attached or elevated decks, with inspections at footing and framing stages. Confirm who applies for the permit and who is present for inspections.
What drives the cost of a deck
Footprint and height are the starting point: a small ground-level deck needs simple footings, while a deck attached at a second-story door needs deeper footings, stronger framing and code-compliant guardrails — all of which add material and labor.
Ground conditions decide how much of that structural cost is predictable. Firm, level soil makes for straightforward footings; sloped, wet or poor-bearing soil can mean deeper piers or engineered footings that only become clear once digging starts.
Decking material is the visible cost but often not the largest one: pressure-treated lumber is the least expensive to install, while composite and hardwood decking cost more per square foot. Attachment to the house — the ledger board connection — is a small part of the job by area but a major focus for inspectors, since a poorly flashed or fastened ledger is a common cause of both failed inspections and later water damage.
A worked example
Take Seattle, the city with the most filings behind its figures (1,966). Suppose two contractors quote for the same deck / decking build: one at about $30,000, in line with the local median, and another at about $120,000, well above the local P75 of $100,000.
Neither figure alone says which contractor is right: $30,000 sits where most Seattle filings land, a reasonable opening point, while $120,000 sits above where three-quarters of them do — not necessarily a red flag, since a raised structure needing deeper footings, difficult ground conditions or hardwood decking can all justify it — but a scope worth having spelled out before you sign. Both figures are illustrative.
What a deck permit valuation leaves out
The filed valuation generally covers footings, framing, decking, stairs and railings for the permitted footprint. It is a declared figure at the time of application, not a reconciled final invoice.
Work discovered once an old deck is removed — rotten ledger framing, undersized existing footings, or rot in the house's rim joist behind the ledger — is rarely priced into the original filing, because it isn't visible until demolition starts.
Landscaping around the new deck, outdoor lighting, and any retaining wall needed to manage a slope are commonly quoted, and sometimes permitted, separately from the deck structure itself.
Use your quote to test the range
What this project can cover
Deck work can cover footings, framing, decking, stairs, railings, and finishes for the permitted footprint and height.
What may sit outside it
Difficult excavation, retaining walls, landscaping, drainage, lighting, and replacement of damaged existing structure may be outside the base scope.
Checks before you accept a quote
Compare footprint, elevation, material, and railing requirements.
Ask how footings and excavation are priced if ground conditions change.
Confirm inspection stages and final sealing or staining.
Questions to ask before you sign
What footing depth and type are assumed, and how is a change priced if soil conditions differ once digging starts?
Is the existing ledger connection to the house being inspected and, if needed, repaired as part of this quote?
What decking material and railing system is specified, and is that reflected in the price per square foot?
Are stairs, lighting and any skirting included, or priced separately?
Who pulls the permit and coordinates the footing and framing inspections?
What happens if the footprint or height changes after the permit is filed?
What is the expected lifespan and maintenance schedule for the specified decking material?
Questions people ask
Does this range include replacing the ledger board or house framing behind it?
Only when that work was part of the declared scope. Ledger and framing repairs found once the old deck comes off are a common source of change orders, and they don't always appear in an original filing.
Why do composite decks cost so much more than the figures here suggest?
The range mixes every decking material together. A quote specifying composite or hardwood decking will typically sit toward the upper end of the range, while pressure-treated lumber tends toward the lower end — compare like for like rather than against the overall median.
Is a raised, second-story deck the same project as a ground-level one?
They're filed under the same project type here, but a raised deck typically needs deeper footings and heavier framing, so it tends to sit above the median rather than at it.
Does the range include a roof or pergola over the deck?
Usually not — a covered structure is a materially different scope and is often filed and priced as its own project.