Cost guide
Deck prices depend most on size, height, and what the boards are made of. This page gives you a starting point before anyone comes out to measure. Every number here is an estimate, not a quote.
The national average: about $8,300
National cost guides put the average new deck at about $8,300, with a normal range of about $4,300 to $12,700 (checked October 2026). There's no reliable published average for the Charleston area, so this page starts from the national figures.
That average mixes small ground-level decks with bigger, higher ones. It can't tell you what your deck will cost. Height alone can more than double the price per square foot. National guides put a ground-level deck at about $10 to $20 per square foot and a second-story deck at about $40 to $50.
| Service | What the estimate covers | Estimated range |
|---|---|---|
| Custom deck (wood) | A new pressure-treated wood deck, typical size | $4,300 to $12,700 |
| Composite deck | A new composite deck, installed | $25 to $54 per sq ft (typical range); about $7,500 to $16,200 for 300 sq ft |
| Porch | Screening an existing 200 sq ft porch | $2,000 to $2,800 |
| Porch | Building a new screened porch with a roof | $4,600 to $22,000 |
| Deck replacement | Removing the old deck, before the new one | $5 to $15 per sq ft (typical range); about $1,500 to $4,500 for 300 sq ft, plus the new deck |
| Pergola | A new pergola, typical size | $2,100 to $6,400 |
All figures are national estimates. The per-square-foot numbers are typical installed ranges from national cost guides. The 300 sq ft examples multiply those ranges out. Your written quote is the real number.
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What pushes a price up
- Height. Second-story decks cost far more per square foot than decks near the ground.
- Composite or PVC boards instead of pressure-treated pine
- Stainless steel screws and hardware near salt water
- Long stairs, landings, and lots of railing
- Removing an old deck, plus any rot or termite damage found behind it
- A porch roof, a finished ceiling, and fan or light wiring
- A lot in a V flood zone, where the City of Charleston's standard deck details don't apply and the deck needs its own design
- Building around a protected tree
- Hot tubs, built-in benches, planters, or privacy screens, which the city's standard deck details don't cover
What brings a price down
- A low deck close to the ground
- A simple rectangle with one set of stairs
- Pressure-treated pine boards
- Easy access to the backyard
- A sound frame you can keep, with only new boards and railings
The fastest way to a real number is a look at the site. Send the form or call (854) 777-0103 for a free quote. We'll measure, check the house connection and the ground, and give you a written price.
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Tell us what you want built and which town you're in. We'll call to set up a free on-site quote.