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Chicago — Tier-1 Pillar

Chicago Deck + Patio — Pressure-Treated, Composite, Freeze-Thaw, CDOB Permit

Chicago deck reality. Pressure-treated southern yellow pine dominates, composite (Trex, TimberTech) for low-maintenance, freeze-thaw cycle kills untreated wood, CDOB Easy Permit for non-structural, Standard Plan for elevated or attached. $14K-$65K typical.

~1 min read·Updated 2026-04-23

Chicago freeze-thaw cycles destroy untreated wood. Pressure-treated southern yellow pine is the baseline; composite (Trex, TimberTech) trades higher upfront cost for zero annual maintenance. Ground-level patios use concrete pavers or bluestone with sand set.

Frequently asked questions

Do I need a permit for a Chicago deck? Yes — any deck over 30" above grade requires CDOB permit. Ground-level patios over existing grade: typically non-permit.

Pressure-treated or composite in Chicago? Composite (Trex, TimberTech, Fiberon) for zero-maintenance and UV-stable color. Pressure-treated for lower cost + natural aesthetic but requires annual sealing.

How much does a Chicago deck cost? PT pine deck: $35-$60/sqft installed. Composite: $55-$95/sqft. Typical 300 sqft deck: $14K-$28K PT or $22K-$42K composite.

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