Deck Building Cost in Illinois (2026)
Deck Building in Illinois runs about 8% above the national average. A typical 320 sq ft project starts around $5,180–$8,640 for pressure-treated wood. Estimate your exact project below.
Illinois runs above the national average on cost, with the Chicago metro labor market and its prevailing wages a major driver, while downstate areas tend to be more affordable.
Reviewed by the AnyCoster Research Team · How we estimate costs
Deck Building Cost Calculator
Adjust the details for an installed-cost range tailored to you.
Length × width of the deck surface. A 16×20 deck is 320 sq ft.
Ballpark estimate for planning — not a quote.
Get your exact price from local deck pros
This is a ballpark — compare up to 3 free, no-obligation quotes from vetted contractors in Illinois.
Deck Building cost in Illinois by material
Installed cost for a typical 320 sq ft project in Illinois.
| Material | Per sq ft | Typical IL project |
|---|---|---|
| Pressure-treated wood | $16.2–$27.0 | $5,180 – $8,640 |
| Cedar / redwood | $27.0–$43.2 | $8,640 – $13,820 |
| Composite (Trex-style) | $32.4–$64.8 | $10,370 – $20,740 |
What affects your Illinois cost
- Decking material and railing style
- Height off the ground and stairs
- Footings, framing and permits
- Built-ins (benches, pergola, lighting)
- Local labor rates
Deck Building in Illinois: local factors that move the price
Climate & weather
Cold, snowy winters and hot, humid summers create strong freeze-thaw stress, and the state's exposure to severe storms and occasional tornadoes matters for exterior durability. Wind and moisture management are both relevant.
Regional norms in Illinois
Brick and vinyl siding are common, with steeply pitched roofs to shed snow.
Best time to schedule
Late spring through fall is the reliable window for exterior work before winter cold sets in.
Permits & code
Chicago and many Illinois municipalities enforce their own building codes and require permits for structural, roofing, and electrical work.
Illinois deck building — FAQ
How much does deck building cost in Illinois?
In Illinois, a typical 320 sq ft deck building project runs about $5,180–$8,640 for pressure-treated wood, installed. That's about 8% above the national average. Higher-end materials cost more — use the calculator above for your exact size and material.
How much does deck building cost per sq ft in Illinois?
In Illinois, installed deck runs about $16.2–$64.8 per sq ft depending on material (pressure-treated wood $16.2–$27.0, cedar / redwood $27.0–$43.2, composite (trex-style) $32.4–$64.8). That's about 8% above the national average.
Do I need a permit for deck building in Illinois?
Chicago and many Illinois municipalities enforce their own building codes and require permits for structural, roofing, and electrical work. Always confirm requirements with your local building department, and factor permit time and inspections into your schedule.
When is the best time to do deck building in Illinois?
Late spring through fall is the reliable window for exterior work before winter cold sets in. Cold, snowy winters and hot, humid summers create strong freeze-thaw stress, and the state's exposure to severe storms and occasional tornadoes matters for exterior durability. Wind and moisture management are both relevant.
How much does it cost to build a deck in 2026?
A typical 320 sq ft deck runs about $5,000–$8,000 in pressure-treated wood, or $10,000–$19,000 in composite, installed. Size, height, railings and material drive the price — use the calculator for a localized estimate.
Is composite decking worth it?
Composite costs roughly 1.5–2× wood up front but eliminates staining/sealing and lasts 25–30+ years, so total cost of ownership is often lower. It's the popular choice for homeowners who don't want annual maintenance.
Top cities in Illinois
Metro-level deck building costs — usually a bit above the Illinois state average.