How Much Does It Cost to Build a 20x20 Wood Deck?

The cost to build a 20×20 wood deck typically starts at $28,000, depending on materials, site conditions, and added features like stairs or custom railing. In our market here in the Birmingham area, that starting price includes permitting, framing, stairs, and cleanup. This size of deck provides 400 square feet of outdoor living space, which is perfect for dining, lounging, or entertaining.

In this guide, we’ll break down the full scope of work, explain what drives the cost, and give you the tools to compare deck sizes and materials to plan your budget.

Timothy Beckham

A licensed home remodeling expert with 25 years of experience, Timothy has helped countless homeowners tackle repairs, manage renovations, and make informed decisions about maintaining their homes.

Last Updated 4/4/2025 | Decks

Breaking Down the Cost of a 20x20 Wood Deck

Here is a real-world scope of work and pricing example from a recent 20×20 pressure-treated wood deck we built:

Scope of Work

Permits and Inspections
We will obtain all required building permits and coordinate necessary inspections with the local building department to ensure full code compliance from start to finish.

Deck Demolition and Construction – $22,000
We’ll fully remove the existing deck and haul all debris to the landfill. The new 20×20 deck will be constructed using pressure-treated 2×12 joists and matching 2×12 outer band framing. Joists will be secured with galvanized metal hangers for long-term strength. All footers will be dug to code, inspected, and poured prior to framing. Once cleared, we’ll install all structural posts, ledger board, and support framing. The deck surface will feature pressure-treated decking boards, and we’ll build new handrails on all exposed sides in accordance with current code.

Stair Construction – $6,000
A new 48-inch wide stairway will be built on the right side of the deck (as viewed from the backyard). It will feature approximately 16 steps with a mid-point landing turning to the right toward the yard. Stairs will include pressure-treated kickplates, risers, and treads. Handrails will be installed on both sides for safety and code compliance.

Debris Removal and Cleanup
After construction is complete, we’ll remove all tools, scrap material, and job-related debris. The yard will be left clean and ready to enjoy.

Total Project Investment: $28,000

Looking for Price of a Custom Deck Project?

If you’re exploring pricing for different sized decks, railing options, and a rain gutter add-on, check out our 12×18 Deck Project Cost Guide or our 12×12 deck price guide for another recent build. It’s a great reference point for comparing deck sizes and material choices.

Ready to Build or Replace Your Deck?

Whether you’re dreaming of a brand-new deck, need help with repairs, or are planning a full tear-down and rebuild, we’ve got you covered. Our licensed team offers expert deck building services, responsive local deck repairs, and professional deck replacements. Looking for something more custom? We also specialize in screened in porches to keep out the bugs, and composite decks for long-lasting beauty with less maintenance.

Let’s talk about your project. contact us today to schedule a consultation and get a quote!