The contractor bids your project for a specific price and that is how much it will cost...in theory. For small, simple projects, you can probably count on this contract to work for you and for your contractor.However, for larger and more complex projects, the final cost is likely to be higher.he contractor bids your project for a specific price and that is how much it will cost...in theory. For small, simple projects, you can probably count on this contract to work for you and for your contractor. However, for larger and more complex projects, the final cost is likely to be higher.
Decks are less expensive than most other home additions. And because decks are so popular, they also make homes more marketable and valuable. Here's a look at what they cost. For basic designs using the least expensive lumber, you can expect to pay from about $6 to $8 per square foot of deck area.Even if you choose top-of-the-line redwood lumber or want a hot tub, material costs are still reasonable, anywhere from $20 to $35 per square foot.ere's a look at what they cost. For basic designs using the least expensive lumber, you can expect to pay from about $6 to $8 per square foot of deck area. Even if you choose top-of-the-line redwood lumber or want a hot tub, material costs are still reasonable, anywhere from $20 to $35 per square foot.
Contractor prices vary widely depending on the type of wood you choose and the size and configuration of the deck. The average price to build a deck with pressure-treated pine is about $30 to $35 per square foot.That price includes the wood planks, supporting framework, railings and all labor costs. Cedar, redwood or wood composites are more expensive, ranging from $35 to $60 per square foot installed. A 16x20 foot deck made with pressure-treated wood would cost $9,600 to $11,200. 2  A 20x20 deck using the same material would cost $12,000 to $14,000. 3  A 16x20 deck using premium wood or wood composites would cost $11,200 to $19,200.