How Much Does it Cost to Build a Composite Deck?

Are you ready to build a deck that fits your budget? Get a deck material cost estimate with the Trex Cost Calculator tool. Plug in your deck dimensions and answer a few questions to get a quote for the material cost of your new deck. On average, the estimated material cost for a composite deck runs from $21 - $30 per square foot (including substructure, decking, hardware, and fasteners).* Keep in mind, labor costs typically account for about 2/3 of the total cost of your decking project.

Composite Deck Costs by Deck Size

This composite decking price chart provides an estimated breakdown of composite decking costs based on deck size and square footage. It includes essential information on material costs only for various common deck dimensions, helping homeowners accurately estimate expenses. On average, the estimated material cost for a composite deck runs from $21 - $30 per square foot (including substructure, decking, fascia, hardware and fasteners).

*Source: HomeAdvisor "How Much Does it Cost To Build A Deck?" 2022

Deck Size (ft)Square FootageComposite Deck Materials Cost
10 x 10 100$2,100 - $3,800
10 x 12120$2,400 - $4,100
10 x 16160$2,800 - $5,000
10 x 20200$3,400 - $6,100
12 x 12144$2,700 - $4,600
12 x 16192$3,100 - $5,700
12 x 20240$3,700 - $7,200
14 x 20280$4,200 - $8,400
16 x 16256$4,300 - $7,800
16 x 20320$4,800 - $9,600
20 x 20400$6,000 - $12,000
20 x 24480$6,700 - $14,400
20 x 25500$7,700 - $16,300
24 x 24576$8,140 - $17,000

Four Factors That Impact Deck Pricing

The size of your deck makes a big difference in pricing. It helps determine the materials and labour costs needed to build your deck.

The design, shape and chosen product line for your deck will affect material and labour costs depending on its complexity and price point. 

Decking materials could include a substructure, decking, railing, hardware and any design-based add-ons. Depending on the condition of a current substructure, this can also be a size-able portion of cost.

Labour and management account for nearly two-thirds of total costs no matter your deck design. We can help you find an installer or you can build it yourself.

 

How to Determine the Labour Cost of Building a Deck

Consider Professional Rates

If you hire a contractor, your deck size and design (such as a picture frame design, stairs or a multi-level deck plan) will likely affect your contractor’s rate or total labor costs. 

Choose Wisely

When it comes time to pick your contractor, there are a few factors to consider to ensure the best return on your investment. Discover helpful hints and best practices here. 

Services and Fees

Common services and fees associated with a professional build include consultation, permits and licensing, site preparation, insurance and the actual labour cost per hour to build your deck. Each professional has their own rates, but keep reading to learn more about estimating labour costs.

Hire a TrexPro® Installer

Looking for an installer versed in all-things-Trex? Hire a TrexPro® installer. These installers are equipped with talented insight from previous Trex deck projects. Find a Pro near you. 

Labour Cost to Build a Composite Deck

Professional labor costs for deck building vary based on location, size, and complexity. Here's how to estimate these costs to decide whether hiring a professional or DIY is right for you:

  • Labor costs for installing a composite deck typically range from $55-70 per square foot.*
  • This average is based on building a ground-level deck (excluding railing or substructure costs).

Let's explore common deck sizes and estimate the labor costs involved.

*Source: HomeAdvisor "How Much Does it Cost To Build A Deck?" 2022

How much does a 3m x 4m deck cost?

Factor in the price of the Trex materials needed for 12m2 of decking area. Then, use the Cost Calculator to determine how much this will cost depending on your selected decking line. The labour cost for a professional to install a composite deck runs from $170-$210 on average* per square metre. This average is based on the labour cost to build a ground-level deck (not including costs associated with installing railing or a substructure). Labour costs depend on a contractor's specific rates and fees, but a good estimate is $2,100 to $2,500* total on a 3m x 4m deck. This doesn't account for additional fees and services like a consultation.

 

How much does a 4m x 5m deck cost?

Follow the same method for a slightly longer deck. Here, we'll be working with 20m2 of deck area. You might expect professional labour costs to be around $3,400-$4,200*. You can see how even a small increase in your deck size can have significant cost implications.

 

How much does a 5m x 5m deck cost?

A 5m x 5m deck is a total of 25m2 of materials and will likely run you upwards of $4,250-$5,250* for professional installation.


Decking Decisions: DIY Deck Build or Hire a Deck Contractor?

Your choice will affect costs, time and responsibility. We're here to help you figure out what's best for you.
 

If you choose to DIY, the total cost to build a deck typically amounts to less than it would to hire a professional. However, you'll be responsible for buying (or renting) the necessary tools and materials, planning deck dimensions, obtaining building codes and more. Take our quiz to see if you're ready to DIY.
 

If you hire a contractor, you'll save time, energy and money on equipment. You'll also have a trusted partner with extensive building knowledge to help you see your project through. However, you'll need to consider the professional's rate and fees associated with your project. 

 
Explore Trex Academy Find an Installer

How to Determine the Cost of Building Your Own Deck

Determine Square Footage

First things first, determine your deck’s square footage by multiplying the length of your deck by the width. Don’t forget to factor in any additional areas like stair landings and odd shapes. 

Factor in Materials

Gather the Trex® decking and materials needed for your DIY build, including your Trex Hideaway® Hidden Fasteners and railing. 

Use Our Cost Calculator

To receive an estimated cost for your materials, use our Cost Calculator Tool. Just plug in your deck dimensions and answer a couple of easy questions. 

Find Your Building Codes

Keep in mind, there might be costs associated with obtaining your local building codes. To find the latest building codes and procedures for your area, visit your local government website or contact them directly. 

Stock Up on Equipment

Do you have the tools and equipment you need? If you’re starting without a timber frame, you might need more than you think, but you can often rent equipment from your local hardware store. 

Keep Time in Mind

Time and energy can be overlooked expenditures. Depending on the complexity of the deck design, expect to spend several weekends with hard (but gratifying) work on preparing the site and building your new deck. 

WANT TO ADD A LITTLE EXTRA?
Fencing
Where to Buy
Trex® Outdoor DeckLighting
Where to Buy


Want to add a little extra?

  • Trex® Railing allows you to lean into the view without obstructing it.
  • Conceal rough edges and bridge unsightly gaps with Trex® Fascia a subtle and sophisticated finishing touch.
  • Trex® OutdoorLighting™ transforms your outdoor space from invisible to inviting, keeping the party going long-after the sun goes down.

Building within a budget?

  • Do it yourself or hire a deck installer in the off-season to save on installation fees.
  • Opt for straight sections of decking and stairs over more complicated curved designs.
  • Creative design and decor, like a mix and match colour scheme, will add style without increasing costs.
  • Look into financing options to put the luxury deck you want within reach.
  • Get more use out of your space with efficient features like outdoor storage solutions.
Estimate Deck Costs

*Average price range excludes Trex Signature® decking, our luxury decking collection. Trex actual material costs and install costs can and will vary based on geographic area, site location, seasonality, design complexity, whether the product is stocked locally, and additional features such as stairs, angles, curves, lighting, etc. For most professionally installed projects, materials constitute up to one third of the total cost.

 

Are you ready to build a deck that fits your budget? Get a deck material cost estimate with the Cost Calculator tool - plug in your deck dimensions and answer a few questions to get a quote for your new deck. On average, the estimated material cost for a composite deck runs from $215 - $265 per square metre (including substructure, decking, hardware and fasteners).*

This content was partially or fully generated by AI and has been reviewed by our team to ensure accuracy and relevance.

Copyright © 2025 Trex Company, Inc. All rights reserved.

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