Second-story deck cost
A deck off a second floor costs more than the same deck at ground level, and the extra is not in the boards. It is in tall posts, bigger footings, bracing, a full-height stair and usually engineering. Here is a 12x16 elevated deck priced line by line with the calculators on this site.
What height does to the price
The same 16x12 pressure-treated deck, priced at three heights with the wood deck cost calculator, and the composite version from the composite deck cost calculator:
| Height | Pressure-treated, installed | Composite, installed |
|---|---|---|
| Ground level (under 2 ft) | $3,421-$4,372 ($18-$23 per sq ft) | $7,465-$9,539 ($39-$50 per sq ft) |
| Standard (2-6 ft) | $3,802-$4,858 ($20-$25 per sq ft) | $8,294-$10,598 ($43-$55 per sq ft) |
| Second storey (about 9-10 ft) | $5,132-$6,558 ($27-$34 per sq ft) | $11,197-$14,308 ($58-$75 per sq ft) |
Going up a storey adds about 35% to the platform alone. The lines below are what make up that difference, and what gets added on top of it.
The structure: posts and footings
At 9 ft the deck materials calculator switches to 6x6 posts and 16 inch footings. For a 16x12 deck attached to the house with a ledger:
| Line | At 3 ft high | At 9 ft high |
|---|---|---|
| Posts | 3 x 4x4, 5.5 ft long | 3 x 6x6, 11.5 ft long |
| Footings | 3 at 12 in diameter | 3 at 16 in diameter |
| Concrete at 42 in deep (60 lb bags) | 8 per footing, 24 in all | 14 per footing, 42 in all |
| Post cost in the takeoff | $51 | $224 |
| Materials, pressure-treated | $2,047-$2,625 | $2,248-$2,883 |
| Materials, composite boards | $3,184-$4,083 | $3,384-$4,341 |
Concrete figures come from the concrete footing bags calculator. Tall posts also need knee bracing or a post-to-beam connector rated for lateral load, and the ledger has to be bolted and flashed to the house rim; the deck ledger board guide covers both.
The stair is a project of its own
A 108 inch rise to the ground needs a full flight. The deck stairs cost calculator works it out:
| Line | Figure |
|---|---|
| Steps | 15 risers, 14 treads, 7.2 in rise each |
| Total run | 12 ft 3 in of yard |
| Installed, rail on one side | $1,816-$3,352 |
| Installed, rails both sides | $2,302-$4,324 |
A 12 ft run takes a lot of yard. Many second-storey decks use a landing and turn the stair 90 degrees, which shortens the run but adds a small platform with its own posts. The deck stair code guide lists the rise, run and landing rules.
Railing, permit and engineering
- Railing is required: a deck 9 ft up is far past the 30 in trigger. The three open sides of a 16x12 deck are about 40 ft, which the deck railing calculator prices at $2,380-$3,360 in composite.
- A permit is almost certain at this height. The deck permit cost calculator puts a $6,000 project at about $237 in fees, which vary widely by town.
- Many building departments want stamped drawings for elevated decks. The multi-level deck cost calculator allows $1,200 for engineering and stamped plans.
- If the space below will be used, add under-deck drainage: about $1,536-$3,840 installed for 192 sq ft. See under deck drainage systems.
Adding it up: a 12x16 second-story deck
| Line | Pressure-treated | Composite |
|---|---|---|
| Deck platform, installed, at second-storey height | $5,132-$6,558 | $11,197-$14,308 |
| Full-height stair, one rail | $1,816-$3,352 | $1,816-$3,352 (pressure-treated stair) |
| Railing upgrade to composite, 40 ft | Optional | $2,380-$3,360 |
| Permit | About $237 | About $237 |
| Engineering, if required | Up to $1,200 | Up to $1,200 |
| Realistic total | About $7,200-$11,300 | About $15,600-$22,500 |
Under-deck drainage, lighting and a roof are extra; the deck roof cost calculator prices a covered deck. For your own size, start with the deck cost calculator and add the stair and railing lines from this page.
Ways to keep it down
- Keep the deck within one joist length of the house (12 ft is efficient) so one beam carries the outer edge.
- Build the frame in pressure-treated lumber even if the boards are composite; that is standard practice and costs much less than a steel or aluminium frame.
- Do the decking, stain and railing infill yourself after a contractor builds and inspects the structure.
- Price the frame and the finish separately, and check the quote with the deck quote checker.
Hardware for the 9 ft high 12x16 deck
Quantities from the deck materials calculator for the worked example above. Lumber and concrete are listed to buy locally; change the size in the calculator for your own deck.
🛒 Your deck materials list
#ad · Amazon- Coated deck screws, #10 × 2-1/2 in2 boxes of 300 screws
- 2x10 joist hangers2 packs of 25 for 26 joist ends
- Joist hanger nails, 1-1/2 in galvanized1 box of 2,000 (260 needed)
- Butyl joist tape for the joist tops5 rolls of 50 ft for 233 ft of joist tops
- Ledger flashing tape, 4 in1 roll of 75 ft for the 16 ft ledger
- Ledger screws (structural, through the rim joist)14 fasteners, two every 16 in, staggered
- 6x6 post bases for concrete1 pack of 6 for 3 posts
- Structural screws to laminate the 2-ply beam1 pack of 50 for 26 screws
- Deck stain & sealer2 × 1 gal for one coat on 192 sq ft (once new treated wood has dried)
Buy locally (lumberyard or home center; freight-only or not sold on Amazon): decking (pressure-treated 5/4×6) 29 × 16 ft boards · joists 13 × 2×10 × 12 ft · rim joists + ledger 56 lin ft of 2×10 · beam 32 lin ft (2-ply) · posts 3 × 6×6 @ 11.5 ft · concrete 18 × 60 lb bags · footing tubes 3 × 16 in
Adds 8 items with these quantities to your Amazon cart; you review them there before buying. As an Amazon Associate I earn from qualifying purchases.
Choosing the railing for an elevated deck? See our deck railing buying guide.
Materials & tools for this job
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Muzata 4P 50ft Black HDPE Under Deck Drainage System,16" Joist Spacing M081 | Waterproofing Membrane, 0.5 mm Thick HDPE, Wear-Resistant, Solid & Durable, Flexible, Easy Installation
$289.99
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Egadis 4 Pack 36 in x 6 ft Modular Aluminum Porch and Deck Railing Kit | Pioneer in Modular Aluminum Railing Kit, ASTM Certified, Textured AAMA2604 Finish for Deck, Porch & Balcony (4 Post, 4 Panel)
$619.99
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Toriexon Steel Stair Step Riser-2 Pack, 2 Step Stair Stringers for Deck | Sturdy Powder Coating Steel Stair Stringer for Outdoor Steps and Stairs
$49.99
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LIONMAX Lag Screws 6 Inch, Structural Wood Screws #14 x 6, 50-PCS, Black | Heavy Duty Timber Screws 6 Inch, Rust Resistant for Exterior Wood/Log/Deck/Construction, Washer Head, T30 Star Drive with Bit
Save 5%
$18.71Typical price:: $19.70
Prices and savings as of Oct 17, 2026, 4:36 AM UTC. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Shopping for someone? See our backyard gift guide for deck builders & DIYers.
Frequently asked questions
How much does a second-story deck cost?
A 12x16 second-storey deck in pressure-treated pine costs about $5,132-$6,558 for the platform, or roughly $7,200-$11,300 once a full-height stair, the permit and engineering are added. In composite the platform alone is about $11,197-$14,308, so a complete deck lands around $15,600-$22,500.
Why is an elevated deck more expensive?
Taller and thicker posts, larger footings, bracing against sideways movement, a full flight of stairs, a required guardrail and often stamped engineering drawings. The boards cost the same at any height. Together those items add roughly 35% to the platform price, before the stair and railing are counted.
How many stairs does a second-story deck need?
For a deck 9 ft above the ground, about 15 risers of 7.2 inches and 14 treads, which run about 12 ft 3 in out into the yard. Codes cap a single rise at 7-3/4 inches in most places, and a landing that turns the stair can shorten the run on tight lots.
Do you need an engineer for a second-story deck?
Many building departments ask for stamped drawings once a deck is elevated, carries a hot tub, or departs from the prescriptive span tables. Others accept a standard plan that follows the DCA 6 guide. Ask before you draw anything; the multi-level deck calculator allows about $1,200 for engineering.
What size posts does a second-story deck need?
Usually 6x6 posts. Many codes and the DCA 6 guide limit 4x4 posts to short heights, and the deck materials calculator on this site switches to 6x6 posts and 16 inch footings above 6 ft. Tall posts also need bracing or connectors rated for lateral load at the beam.
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