Cost to Build a Deck in St. Louis, MO (2026)
In St. Louis a 12×16 ft deck costs about $4,328 in pressure-treated pine and $9,344 in composite, installed — right in line with the US average. Below: local prices by size, footing depth, permits and a calculator priced for St. Louis.
Pressure-treated pine
$20–$26 /sq ft
Cedar
$28–$37 /sq ft
Composite
$43–$56 /sq ft
Deck cost calculator for St. Louis
Priced with St. Louis labour, material and footing-depth factors. Change any input and the estimate updates.
Estimated installed cost
$8,222 – $10,745
192 sq ft · about $48.66/sq ft
- Materials
- $5,757
- Labour
- $3,586
- Footings (30 in deep)
- 3 × about $186
- Frost-depth adjustment
- +$58
Mid-range estimate for a rectangular deck attached to the house, with one beam line per 12 ft of depth and footings every 8 ft. Excludes demolition, permits and site work. For railing, stairs and a full line-item breakdown use the main deck cost calculator.
St. Louis deck cost by size and material
Mid-range installed prices for a standard-height deck attached to the house, with footings at 30 inches. Add railing and stairs in the deck cost calculator.
| Deck size | Pressure-treated pine | Cedar | Composite |
|---|---|---|---|
| 10 × 10 ft (100 sq ft) | $2,282 | $3,286 | $4,894 |
| 12 × 12 ft (144 sq ft) | $3,260 | $4,707 | $7,022 |
| 12 × 16 ft (192 sq ft) | $4,328 | $6,257 | $9,344 |
| 16 × 20 ft (320 sq ft) | $7,271 | $10,486 | $15,630 |
| 20 × 20 ft (400 sq ft) | $9,050 | $13,069 | $19,500 |
What makes a deck in St. Louis cost what it does
Humid summers, freeze-thaw winters and older brick homes with rear decks.
Labour here runs 2% above the Missouri average, so a pressure-treated 12×16 that averages $4,282 across Missouri comes to about $4,328 in St. Louis. Hot, humid summers, cold winters and severe spring storms.
Footings
Footings in St. Louis go about 30 inches deep, which costs roughly $186 per 12 inch footing installed. A 12×16 deck needs about 3. Size them with the deck footing calculator.
Deck permits in St. Louis
Permits are issued by the City of St. Louis Building Division / St. Louis County. The city and county issue separate permits; footings typically go 30 inches deep. Typical fees run $150–$450. For the state rules that sit behind the local ones, see deck cost in Missouri.
Choosing decking in St. Louis
Composite adds about $5,016 to a 12×16 deck here over pressure-treated. A mid-cost state where pressure-treated remains the value option. Run the numbers for your deck in the composite vs wood calculator.
Best time to build
April to June and September to November.
Other Missouri cities
- Kansas City — 12×16 composite about $9,331
Frequently asked questions
How much does a deck cost in St. Louis?
A 12×16 ft deck in St. Louis costs about $4,328 in pressure-treated pine, $6,257 in cedar and $9,344 in composite, installed. That is $20–$26 per square foot for pressure-treated and $43–$56 for composite.
Is building a deck in St. Louis more expensive than elsewhere in Missouri?
A typical deck in St. Louis runs right in line with the Missouri average and right in line with the US average, mainly because of local labour rates. Humid summers, freeze-thaw winters and older brick homes with rear decks.
Do I need a permit for a deck in St. Louis?
Permits are issued by the City of St. Louis Building Division / St. Louis County. The city and county issue separate permits; footings typically go 30 inches deep. Budget roughly $150–$450 for the permit, more if drawings by a design professional are required.
How deep do deck footings have to be in St. Louis?
About 30 inches. Each 12 inch footing at that depth costs roughly $186 installed, and a 12×16 deck needs about 3. Always confirm the required depth with the City of St. Louis Building Division / St. Louis County before digging — the footing inspection happens before any concrete goes in.
Should I choose composite or wood for a deck in St. Louis?
Composite adds about $5,016 to a 12×16 deck in St. Louis but removes staining every two to three years. A mid-cost state where pressure-treated remains the value option.
Price the rest of the project
Figures are planning estimates built from national installed prices adjusted for Missouri and St. Louis labour, materials and footing depth. Get two or three itemised local quotes. Method.