In 2026, building a deck in Knoxville typically costs $30–$60 per square foot for pressure-treated wood, $55–$95 per square foot for composite, and $100+ per square foot for premium hardwood or multi-level designs. A common 300–400 sq ft deck usually lands between $12,000 and $30,000 installed, depending on material, height off the ground, railings, and features. Below is how those numbers break down and what moves them.
Deck Cost by Material (Knoxville, 2026)
Material is the single biggest factor in deck cost. Here are typical installed price ranges for the East Tennessee market:
| Decking material | Installed cost / sq ft | Lifespan | Maintenance |
|---|---|---|---|
| Pressure-treated pine | $30–$60 | 10–15 yrs | Seal annually |
| Composite (Trex, TimberTech, Fiberon) | $55–$95 | 25–30+ yrs | Wash only |
| Premium hardwood (Ipe, Tigerwood) | $100+ | 25–40 yrs | Oil periodically |
Ranges are general East-Tennessee planning figures for 2026, not a quote. Your written StructureWorks estimate is specific to your project.
What Drives the Price Up or Down
Two decks of the same size can differ in price by thousands of dollars. The biggest variables in the Knoxville area are:
- Height off the ground — elevated decks on sloped East TN lots need taller posts, bigger footings, and often stairs, all of which add cost.
- Railing system — basic wood rail is cheapest; aluminum, cable, and glass railings cost more but last longer and look cleaner.
- Footings & framing — frost-depth footings and proper ledger flashing are required by code and protect your home from water damage.
- Shape & levels — multi-level decks, angles, and built-in seating or planters increase labor.
- Add-ons — stairs, lighting, pergolas, and screened enclosures each add to the total.
Permits & Code in Knox County
Decks attached to a home or above a certain height require a building permit in Knox County and the City of Knoxville, and must meet IRC code for footing depth, ledger attachment, railing height (36" residential), and baluster spacing (4" max). StructureWorks pulls the permits and builds to code so your deck passes inspection and protects your home. For a broader overview, see our Knox County permit guide.
Composite vs. Wood in East Tennessee's Climate
Tennessee's humid summers and freeze-thaw winters are hard on wood. Pressure-treated lumber is the lowest upfront cost but needs annual sealing and will eventually warp, crack, or splinter. Composite decking costs more initially but shrugs off moisture and insects, never needs staining, and commonly lasts 25+ years — which is why many Knoxville homeowners choose it as the better long-term value. We help you compare both against your budget.
Get an Exact Deck Quote
The fastest way to know your real number is a free on-site estimate. StructureWorks designs and builds custom composite and wood decks, porches, and outdoor living spaces across Knoxville and East Tennessee. Request a free deck quote or call (865) 630-4073.