How Much Does a 12x12 Composite Deck Cost?

composite decking boards

If you want to build a deck for your property, choosing a 12x12 composite design is a smart choice. But how much does a 12x12 composite deck cost you overall and why should you choose this option over all the others you might pick instead?

Why a 12x12 Composite Deck?

According to various statistics, the most common deck size for U.S. homes is between 144 to 300 square feet. A 12x12 deck provides 144 square feet of space, which is a typical size for apartments, condos, and city homes.

This is not a large deck, but it is enough space for some furniture and some moving around space. This provides some extra outdoor living space in a size that is easy to maintain and, importantly, easy to build as a DIY project.

Composite material is any combination of two materials. Lots of different building materials are a type of composite, including reinforced concrete and many types of wood that are commonly found in decking and outdoor structures.

Engineered wood, parquet floors, wood-plastic composite, cement-bonded wood, and fiberglass are all types of composite. These materials are popular in building projects of all kinds.

Composites date back at least as far as ancient Egypt, when builders here used a type of plywood to construct some of their incredible monuments.

Why use composite? Blended materials like this often contain the qualities of both materials. Hence, you get the water resistance of plastic and the look of wood in a single building material, for example.

Composite decking is a mixture of wood fibers, recycled plastic, and chemical agents used to bond them together to create one unified material that has great moisture resistance and strength. These two materials create a highly durable yet beautiful decking that is low-maintenance and long-wearing.

The Advantages of a Composite Deck

A composite deck will pay for itself in time. An average composite deck lasts for twice as long as a deck built in wood. Real wood must also be re-stained and re-treated every few years in order to maintain its beauty.

Composite decking is made with sterner stuff. It is weather-resistant and will not rot, warp, or splinter.

Composite material is fade- and stain-resistant. It's also resistant to the growth of mold and mildew, and it doesn't get eaten by insects.

Another good thing about composition is its eco-friendliness. It's made from recycled materials, and it's a low-maintenance material that is easy to clean and maintain.

Composite decking does not need to be stained and sealed. Compare this to wood decking, which must be stained and sealed every few years in order to maintain its appearance.

Composite is highly wear-resistant, low-maintenance, and hard-wearing, all qualities that are wonderful to have in a deck or, in fact, any outdoor structure. You can also build a deck in composite yourself as easily as you could build one in wood, which makes this an excellent choice for DIYers.

composite deck

What Does It Cost to Build a Deck?

A lot goes into building a deck. However, this is a project that is very DIY-friendly, and you can calculate the costs of this type of deck rather easily.

To calculate the cost of the deck, you will need to figure out the cost of not just the wood used to build the deck but also all the various materials required to complete the project. This includes nails, wood glue, and everything else you need to pull this project together.

The cost of the deck will also vary based on how many additions and extras you want to add. How many stairs you plan to add, extras like railings and built-in seating—all of this will add to the cost of your deck.


On average, composite decking ranges from $5 to $13 per square foot. This means that your deck project for a 12x12 plan will cost you, on average, $2,600 for the wood alone.

This price includes supports under the deck, the deck surface itself, along with railings, and one set of stairs. However, there are additional elements that go into building a deck that will add to this overall cost.

Extra Costs

There are some little extras that can make your deck area even nicer and don't cost a lot of money. Consider paying the cost of these extras in order to get even more out of your deck area.

Place landscape fabric under the deck to prevent weed growth. This fabric is a highly affordable solution, as it only costs around $30 for an entire roll.

It’s also very easy to place this fabric. Preventing weed growth also prevents insects, which can make any outdoor space supremely uncomfortable.

Use concrete footings to give the deck great support. It costs a little more to get concrete, and it can be a bit labor-intensive to pour the concrete, but there is no substitute for this extra care and attention to detail in your build.


To give your deck a finished look, you will want to include some sort of skirting if your deck is raised off the ground. The skirting covers the supports of the deck and blocks in the area beneath the deck.

You may want to consider vinyl lattice skirting, which will cost around $1,000. This skirting has a trellis-like look, and it's very popular in deck design.

The lattice look is highly popular in decking because it allows airflow to get under the deck. This provides natural drying for moisture that may collect under the deck, which prevents the growth of mold and mildew.

However, there are multiple options when it comes to deck skirting. You can also choose not to use skirting at all.

Skirting gives the deck a finished look. It also prevents animals and debris from getting under your deck. If you can afford to add this to your budget, do it.

composite deck with siding


Is your deck fully exposed to the sun? Not only can the sun make an outdoor living space a lot less comfortable, but it will also do damage to your deck furnishings over time.

You will want to give your deck some shade if there are no nearby trees to provide this naturally. Installing an awning or a roof on your deck will add more to the total cost of this project.

Adding shade will make this space much more pleasant and make it possible to use your deck in all weather conditions.

Other Issues

Everything's all well and good when you first decide to build a deck. Then you get to work on the project...and you run into problems.

With every DIY project, there are problems that will arise. One major issue can be structural obstacles you didn't know were present.

Pipes, electrical wiring, even large rocks and roots can pose big structural hazards when it's time to build a deck. The cost of removing or rerouting these items can add a lot to your total project cost.

Wiring and pipes might need to be totally re-routed, where large rocks and roots must be removed. If you do run into infrastructure hazards like wires or pipes, you will need to consult with a professional to find out if and how these elements must be re-routed.

Issues such as this can end up costing you more in both time and money. However, it’s wise to budget a few hundred extra dollars and an extra week of work time because most likely, these issues will arise.

Should no major problems happen, count yourself quite lucky. You may even finish the project ahead of schedule and slightly under budget, thanks to your careful planning and attention to detail!


It's easy to focus on getting the deck built and forget about practical elements, like lights. Even if you can't afford furniture right away, you will need lighting so you can see your deck area.

This problem may be solved with a simple light by the door or you may need something more elaborate, but remember to factor this into the total cost of your project and don't forget this necessary additional detail.

If you’re going to have lighting—and you should—remember too that you will need electricity or some other power source for this light. If you're using solar-powered lights, installation is quite easy.

However, you may want gas-powered tiki torches or more traditional electric lighting. Choose the type of lighting you want before you start to build, so you can be aware of any special infrastructure you might need to light the deck up the way you want.

You may need to consult with a professional to have electrical wiring and outlets put in place or to have gas piping installed. This will add several hundred dollars to the cost of your total deck project.

Composite Compared to Other Decks

How do the costs of a composite deck compare to decking made with other materials that are commonly used?

Per square foot of finished decking, composite costs between $20 to $38 per square foot. This price includes all related installation materials.

Compare this cost to pressure-treated wood, which costs between $15 and $25 per square foot. Cedar wood, a popular decking choice, will cost $30 and up per square foot.

PVC, polypropylene plastic, costs around $4 per square foot for decking. All of these materials are commonly used in decking, and all have their own pros and cons.

composite deck under construction

How Much Does a 12x12 Composite Deck Cost?

So, how much will your deck cost if it is made from composite decking and measures 12x12 feet? Based on average costs, the total price of the project varies greatly depending on the design decisions you make.

A ground-level deck in a simple design will be around $2,000. This is about as affordable as it will get when it comes to building a deck, unless you can get some really good bargains on materials.

For a deck with a railing that is raised off the ground, you will spend closer to $6,000. If you're going to add lots of bells and whistles, including a roof and all that, you may spend closer to $10,000 to complete the total project.

People Also Ask

How long does it take to install a deck?

The actual physical act of installing a deck can take as little as two days, even one day if there are multiple hands at work. However, buying materials, obtaining permits, and planning out the deck can add weeks to the project.

For most people, it takes three to four weeks to completely build a deck from start to finish. Within this time frame, however, you're looking at around three to four days of actual building work.

For the most part, you'll lay the groundwork and prep the area on the first day of construction. Actually building the deck and putting all the wood in place will take a full day, perhaps two or three.

Staining and finishing the deck will take another day's work. It's not until this is done that the deck can be called a finished project.

How long will a composite deck last?

Composite decking continues to look good and function well with regular light maintenance for 25 to 30 years, which is considered to be a lifetime span. This length of time is about the same as an average home mortgage.

How do you maintain a composite deck?

Composite decks must be cleaned regularly, usually about twice a year. To do this, you need only spray the deck with soapy water and scrub gently with a soft bristle brush.

The deck should then be rinsed off thoroughly and then allowed to dry naturally.

Otherwise, sweep the decking regularly to remove debris. Pull out any items that slip down between boards.

Further Reading

Composite Decking Material: Maintenance and Repair

Freestanding Deck Building Instructions

How to Pressure Wash a Composite Deck

Unique Deck Designs

Wood, Vinyl or Metal Deck Railings?