Deck Building Cost in Chicago (2026)

Yes, Chicago requires a permit for any deck more than 30 inches above grade or any deck attached to the house. In 2026, the minimum permit fee for a backyard deck starts at $602.

Composite (mid-grade) is recommended for Chicago's 40–60 annual freeze-thaw cycles. While pressure-treated wood is cheaper at $26–$35/sq ft, composite ($35–$45/sq ft) resists the slush and temperature swings that cause wood to warp and crack.

For a standard 320 sq ft footprint, a pressure-treated wood deck averages $8,300 to $11,200, while a mid-grade composite build typically ranges from $11,200 to $14,400 including labor.

Yes, booking a project for late summer or early fall 2026 can save 5% to 10% on labor costs as demand drops before winter. Spring and early summer are peak seasons with the highest rates and longest wait times.