How to Estimate Deck Addition Costs How to Estimate Deck Addition Costs

What You'll Need
Deck plans

As wonderful as a deck addition on house may look, it can also be expensive. Before you commit yourself to building a deck, you need to know how much it will cost. That means you need a close estimate of the various expenses of your deck addition. With a little time and a calculator, you can do this quite easily. This will enable you to budget correctly and plan for the deck addition of your dreams.

Step 1 - Design

The first stage in estimating the cost of your deck addition is to have a completed design for the deck. When you’ve established that, look at the materials you wish to use and make a decision. From here, you’ll be able to calculate the square footage of the deck itself. To find the figure, multiply the length of the deck by its width.

Step 2 - Decking Costs

Once you know the square footage of the deck, you can come up with the costs of the decking itself. Multiply the cost per square foot of the decking you’ve chosen by the number of square feet in the deck. This gives you the very basic cost of the deck addition. However, there are plenty of other costs such as supports, railing, steps and anything else you want to have on the deck.

Step 3 - Railings

The railings are an important part of a deck addition as an aesthetic and safety feature. To calculate the cost, measure the distance around the edge of your deck other than where it meets the house. Now, you can price the railings, allowing for boards on both top and bottom and the cost of wood for the vertical pieces.

Step 4 - Supports

The deck doesn’t stand directly on the ground; it needs supports and a framework. This is especially true where the deck stands high off the ground. Your design should include the measurements necessary for these. Take the price of the lumber per foot and calculate the cost of supports, adding them to the total for your deck addition.

For steps, you can buy pre-built risers or make them yourself from 2 by 12 inch lumber. Calculate which is cheaper then add in the cost of wood for the steps themselves.

Step 5 - Extras

Finally, you can estimate how much lumber you will needs for extra features of the deck addition. These could include seats that are built in, a gate on the deck plus any hardware that might be necessary.

Having come up with these total costs, however, you’re not yet finished. You’re going to need plenty of screws and nails. The best way to come up with an estimate for all these additional things is to take the cost of the wood then add a figure that’s half as much again. You might not end up spending this much but it will stop you running over budget.

Step 6 - Contractor

If you plan on using a contractor to build your deck addition, the simplest way to estimate the amount is to take the figure for materials and double it. This will give a close figure to the total costs for your deck. However, a contractor will offer a full estimate prior to starting work to establish a final price.

Got a New Project You're Proud of?

Post it on Your Projects!