Deck costs

By material, installed: pressure-treated pine $15–$25 per square foot, cedar $19–$29, redwood $27–$38, composite $28–$40, mahogany $35–$50, ipe $30–$55, vinyl/PVC $17–$33, metal $21–$35. Material-only costs are much lower — pressure-treated $3–$8, composite $8–$20, ipe $10–$20 — which is why a lumberyard price list is a poor guide to an installed quote. Labor alone runs $10 to $35 per square foot.

By size: 8x10 (80 sq ft) $1,200–$4,400; 12x12 (144 sq ft) $2,160–$7,920; 10x16 (160 sq ft) $2,400–$8,800; 12x20 (240 sq ft) $3,600–$13,200; 16x20 (320 sq ft) $4,800–$17,600; 20x20 (400 sq ft) $6,000–$22,000. By deck type: platform $10–$30 per square foot, raised $25–$50, two-story $30–$60, multi-level $30–$75, covered $40–$100.

The add-ons that blow the budget. Railings, installed, per linear foot: wood $30–$50, metal $45–$85, composite $80–$165, cable $115–$175, glass $140–$210. On a 40-foot railing run, that is the difference between about $1,200 and about $8,400. Stairs: $75–$200 per step for wood with pre-cut stringers, $125–$250 with custom stringers, $225–$450 for metal. Permits $100–$500.

Compare bids on the same drawing. Deck quotes are only comparable if every bidder is pricing the same square footage, the same deck height, the same railing material, and the same number of stair treads. Change any one of those and the numbers stop meaning anything. Ask for a line-item breakdown: framing, footings, decking, railing, stairs, permit, and disposal of the old deck.

How to choose

Set the railing budget first

Railing choice can swing a mid-size deck by several thousand dollars on its own, from $30 to $210 per linear foot installed. Decide before you shop, not after.

Ask for material and labor split out

Labor is $10 to $35 per square foot. If a bid won't separate labor from materials, you cannot tell whether you're paying for skill or for markup.

Watch the stair count

Stairs are priced per step, $75 to $450 depending on construction. A deck one step higher off grade is a real cost difference, not a rounding error.

Get demolition and haul-away in writing

Removing an old deck is separate work. If it isn't in the quote, it will arrive as a change order.

Never compare a financed monthly payment to a cash bid

Ask every bidder for the total cash price in writing. Financing markups only become visible when you line the cash numbers up side by side.