How much does a 12×12 deck cost in Boise?

A 12×12 deck is 144 square feet. Using 2026 market ranges, a raised pressure-treated version runs about $3,500–$6,500 and a raised composite version about $5,500–$10,000, before railing and stairs. Fixr's January 2023 national table lists $2,160–$7,920 for the same size. A 144-square-foot deck more than 12 inches high still needs a Boise permit, which adds drawing time.

How much do deck stairs add to the cost?

Fixr's 2023 figures put wood stairs at $75–$200 per step installed with pre-cut stringers, $125–$250 with custom stringers and $225–$450 for metal. A deck about three feet up needs roughly five risers, plus a landing pad at the bottom. Wide or switchback stairs, lighting and a guard on the open sides all add to that line.

Is a deck or a concrete patio cheaper?

On flat ground a slab patio usually costs less per square foot because it needs no framing. A deck wins where the door sits well above grade or the yard slopes, since building a patio up to meet the threshold means fill and retaining. In Boise, a concrete patio more than 12 inches above grade needs a permit too, so the permit step is the same.

What is the cheapest way to build a deck in Boise?

Keep it simple and low. A rectangle under 12 inches high avoids a Boise or Nampa permit (setbacks and HOA rules still apply), needs no guard and uses short posts. Choose pressure-treated decking, size it to standard board lengths to cut waste and skip built-ins. You can upgrade railing or add a cover later if the framing is designed for it.

Why do Boise deck quotes vary so much?

Scope differences explain most of it. One bid may include railing, stairs, the permit and demolition while another quotes decking only. Footing count, joist spacing, the product line and site access also change the price. Ask every contractor to break out the same lines so you compare like for like.

Does a deck need to be built in summer?

No. Framing and decking go in most of the year, but concrete footings need unfrozen ground. Boise averages 108 freezing nights and 16 days that stay below freezing, mostly December through February, so winter pours are slower and less predictable. Late summer and early fall are often easier to schedule than the spring rush.

Deck Cost in Boise, ID (2026)

What does a deck cost per square foot in Boise?

Expect a range, not a number. The installed price of the deck platform itself (footings, framing, decking and labor) runs from $25–$40 per square foot for treated pine up to $55–$78 for PVC in the 2026 market data we compile. Those ranges blend HomeGuide's 2026 national installed-cost pages with published Treasure Valley contractor pricing, rounded. They are the same figures our deck cost calculator uses, and they are not a Valley Decks price list.

Installed deck platform, 2026 market ranges (raised deck, 1–4 ft high). Railing, stairs and demolition are extra.
Decking material	Per sq ft installed	200 sq ft	300 sq ft	400 sq ft
Pressure-treated pine	$25–$40	$4,500–$9,000	$7,000–$13,500	$9,000–$18,000
Western red cedar	$30–$48	$5,500–$11,000	$8,500–$16,000	$11,000–$21,500
Capped composite (e.g. Trex, TimberTech, Fiberon)	$40–$62	$7,500–$14,000	$11,000–$21,000	$14,500–$28,000
PVC / cellular (e.g. AZEK)	$55–$78	$10,000–$17,500	$15,000–$26,000	$20,000–$35,000

Height is the second lever after material. In the same model a ground-level deck (under 12 inches) prices about 10% below a raised one, and a second-story deck about 30% above it. Taller decks need longer posts, bigger beams, diagonal bracing, more stair risers and a full guard, and every one of those is labor. A 300-square-foot composite deck moves from $10,000–$18,500 at ground level to $14,500–$27,000 off a second-floor door.

Published deck cost figures, side by side

Older sources run lower, and the gap tells you how far prices have moved since 2021. The table lines up the per-square-foot figures we could check. Fixr's national page was last updated in January 2023. HomeBlue's Boise page dates to December 2021 and reads low for a 2026 build. HomeGuide's 2026 figures come from its published cost pages.

Installed cost per square foot by source and year (deck platform)
Source (year)	Pressure-treated	Cedar	Composite	PVC
2026 market ranges used on this site	$25–$40	$30–$48	$40–$62	$55–$78
HomeGuide (2026, national)	$25–$50	$30–$50	$40–$80	AZEK: $60–$80
Fixr (Jan 2023, national)	$15–$25	$19–$29	$28–$40	$17–$33
HomeBlue (Dec 2021, Boise)	$17–$20	$29–$32	$33–$35	Not listed

Angi's 2026 deck cost article quotes roughly $30–$60 per square foot overall and a national average project near $8,320; we treat that average with caution because it mixes small ground-level platforms with full builds. Fixr's January 2023 page puts the typical national project at $14,000, describing it as a 320-square-foot composite deck with railings.

Where does the money go on a deck?

Decking boards are only part of the bill. Footings, framing, railing and stairs often add up to more than the surface you walk on, and railing is the line that most often surprises people. Fixr's 2023 component pricing is the most detailed published breakdown we found; treat it as a floor, since it predates two years of lumber and labor increases.

Deck components and published installed costs (Fixr, January 2023, national)
Component	Published installed cost	What drives it in Boise
Poured concrete footing	$200–$350 each	Footings must reach the 24-inch frost depth; more posts mean more holes.
Wood framing (joists, beams)	$12–$25 per sq ft	Joist spacing for the chosen board, beam spans and the 20 psf ground snow load.
Railing, wood	$30–$50 per linear ft	Required on any surface more than 30 in above grade.
Railing, metal	$45–$85 per linear ft	Aluminum is common where views matter.
Railing, composite	$80–$165 per linear ft	Matched to composite decking lines.
Railing, cable / glass	$115–$175 / $140–$210 per linear ft	View decks in the Foothills and on river lots.
Stairs, wood (pre-cut stringers)	$75–$200 per step	Taller decks need more risers and a landing.
Old deck removal	$5–$15 per sq ft	Haul distance and disposal fees.
Permit	$100–$500 (national)	Check the city's current fee schedule.

To see why railing matters, run the math on a common raised deck: 60 linear feet of composite railing at Fixr's 2023 range is $4,800–$9,900 on its own, which can rival the decking surface. Our calculator leaves railing, stairs, demolition, covers and lighting out of its total and lists them as priced at the site visit, because those lines vary too much to guess. For railing choices in more depth, see the deck railing comparison.

Deck framing plan sketch, tape measure and composite board samples on a patio table — Illustration: a deck budget starts with a measured plan, not a per-square-foot guess.

Local factors that move a Boise deck price

Local rules and ground conditions add real cost that national calculators miss. Six factors account for most of the difference between a Treasure Valley bid and a national average.

The 12-inch permit rule in Boise and Nampa

Boise requires a building permit when a deck is more than 12 inches above grade, which is stricter than the 30-inch figure most national articles repeat. Nampa uses the same 12-inch threshold. A permit means drawings: Boise's #402 submittal checklist asks for a site plan with distances to property lines plus deck construction and ledger connection details. Homeowners may pull a Boise permit for their own primary residence, but the drawings still take time to prepare. The Boise deck permit guide walks through the submittal.

Meridian's 200-square-foot and 30-inch exemption

Meridian exempts a deck only when it is detached, 200 square feet or smaller, no more than 30 inches above grade at any point and not serving a required exit door. Attach it to the house, go bigger or go higher and you need a permit. Most attached decks in Meridian subdivisions therefore need one, and setbacks and HOA rules apply either way. Details are on the Meridian deck permit page.

24-inch footings and snow load

Boise's design criteria set the frost line at 24 inches and the ground snow load at 20 pounds per square foot. Footings have to bear below frost, because NOAA's 1991–2020 normals show 108 nights a year at or below freezing and the ground heaves shallow piers. Each footing is a hole, a form and a pour, so a deck with 12 posts costs noticeably more than one with 6. Our footing depth guide explains the sizing.

HOA review

Many newer subdivisions in Meridian, Eagle and Star run architectural review. Third-party permit guides put typical HOA turnaround at one to six weeks, and boards often limit material, color, size and placement. That review can change the spec (and the price) before a board is cut. The Idaho Supreme Court's 2019 Eagle Springs decision upheld an HOA's enforcement against work not built as approved, so build what was approved.

Foothills slope and the wildfire overlay

Sloped Foothills lots need taller posts, more bracing and sometimes an engineer's stamp. Boise's Wildland-Urban Interface overlay applies Class 1 ignition-resistant construction (IR1) in the Foothills, generally north and west of Hill Road. How that applies to a deck surface should be confirmed with Boise Fire before you pick boards, and listed fire-rated decking prices at the top of the PVC band. See wildfire-resistant decking for the Boise Foothills.

Site access

A wide side yard and a truck-friendly driveway keep labor down. Tight North End lots, backyards reached only through a gate, sprinkler lines to relocate and concrete that has to be wheeled in all add hours. None of that shows up in a per-square-foot figure, which is why an on-site measure matters.

Does a new deck add value to a Boise home?

A deck recovers a large share of its cost at resale, and wood recovers more than composite in percentage terms. The 2025 Cost vs. Value report from Remodeling / JLC, in its Mountain region table (which covers Idaho and neighboring states, not Boise alone), lists a wood deck addition at a job cost of $18,253 with an estimated resale value of $17,753, about 97% recouped. The composite version is listed at $26,342 in cost and $21,630 in value, or 82.1%.

Read those as regional survey estimates from real estate professionals, not appraisals. The percentages favor wood because the wood project is cheaper. Composite earns its keep through years without staining, which a resale survey does not capture. The composite vs wood decking guide works through that trade-off.

A checklist for comparing deck quotes

Line up scope before price. Two bids that differ by $8,000 usually describe two different decks, so put each quote through the same checklist.

Same footprint and height on every bid, with square footage written down.
Footing count, diameter and depth stated (24 inches minimum to reach Boise's frost line).
Framing lumber, joist size and joist spacing named, and the spacing matches the decking manufacturer's requirement.
Ledger attachment and flashing described, or a freestanding design explained.
Decking named by brand, product line and color, not just 'composite'.
Railing type and linear footage, plus stair count and landing size.
Permit included, with who prepares drawings and who pulls it.
Demolition and haul-off priced as its own line on replacements.
HOA submittal help, if your neighborhood needs it.
Payment schedule tied to milestones, and the written workmanship terms separate from the manufacturer's product warranty.
The contractor's Idaho registration number, which you can check with the Idaho Division of Occupational and Professional Licenses.

Run the numbers for your own deck

Plug your square footage, material and height into the deck cost calculator to see the same 2026 ranges applied to your size. It shows a low-to-high range rather than one number and flags the add-ons that need a site visit. When the range looks workable, request an estimate and we will measure, check the permit path for your city and price the full scope, including railing and stairs.

Run your own numbers with the deck cost calculator.

Frequently asked questions

How much does a 12×12 deck cost in Boise?: A 12×12 deck is 144 square feet. Using 2026 market ranges, a raised pressure-treated version runs about $3,500–$6,500 and a raised composite version about $5,500–$10,000, before railing and stairs. Fixr's January 2023 national table lists $2,160–$7,920 for the same size. A 144-square-foot deck more than 12 inches high still needs a Boise permit, which adds drawing time.
How much do deck stairs add to the cost?: Fixr's 2023 figures put wood stairs at $75–$200 per step installed with pre-cut stringers, $125–$250 with custom stringers and $225–$450 for metal. A deck about three feet up needs roughly five risers, plus a landing pad at the bottom. Wide or switchback stairs, lighting and a guard on the open sides all add to that line.
Is a deck or a concrete patio cheaper?: On flat ground a slab patio usually costs less per square foot because it needs no framing. A deck wins where the door sits well above grade or the yard slopes, since building a patio up to meet the threshold means fill and retaining. In Boise, a concrete patio more than 12 inches above grade needs a permit too, so the permit step is the same.
What is the cheapest way to build a deck in Boise?: Keep it simple and low. A rectangle under 12 inches high avoids a Boise or Nampa permit (setbacks and HOA rules still apply), needs no guard and uses short posts. Choose pressure-treated decking, size it to standard board lengths to cut waste and skip built-ins. You can upgrade railing or add a cover later if the framing is designed for it.
Why do Boise deck quotes vary so much?: Scope differences explain most of it. One bid may include railing, stairs, the permit and demolition while another quotes decking only. Footing count, joist spacing, the product line and site access also change the price. Ask every contractor to break out the same lines so you compare like for like.
Does a deck need to be built in summer?: No. Framing and decking go in most of the year, but concrete footings need unfrozen ground. Boise averages 108 freezing nights and 16 days that stay below freezing, mostly December through February, so winter pours are slower and less predictable. Late summer and early fall are often easier to schedule than the spring rush.

Sources

Last reviewed October 15, 2026.

How much does a deck cost in Boise, ID?