How to Design a Deck

Three Parts:Choosing Your StylePlanning the SupportsUsing Planning Tools

Some homeowners choose a decking-style because they like the way it looks. Increasingly, however, many homeowners are designing decks to fit in with the style of their home and garden. You may want to consider the proposed function or daily use of the deck by your family, whether it is for entertainment, dining, or a place to play and relax. Get started with Step 1 below for a list of the things you'll have to consider, some helpful tools for designing your deck, and an outlining of how the space and build the structure.

Part 1
Choosing Your Style

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    Choose the attachment options. Do you want your deck attached to your home (meaning it will be adjoined to the walls, use your foundation as a support, and may share a roof)? Or do you want the deck to be detached? The second is the much easier option and will be easier to create a professional look. Attached decks can look very "added on" or "after-thoughty" if not done correctly and skillfully.
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    Choose the height you desire. How high do you want your deck to be? If it's a high deck, especially such as one that is attached to a second story, you may find that there are special requirements demanded by your state. Often, railings of a particular height and style will be requested and special locks on doors may be needed if you have children. Lower decks require fewer supports and are often much easier to build.
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    Account for the terrain. Is your house on a slope? Will your deck be affected? This can change the footing that you need and lead you to have to account for height, but if the slope is very steep, it may not be possible or safe to build a deck at all. If you are concerned about the slope on your property, contact a local building inspector to evaluate your property. Different areas are more or less geologically stable and only a local inspector will know if it's safe for you to put a deck on your property.
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    Add in multiple levels. The decks of yesteryear were flat as the boards that made them, but these days it's all about multi-level decks and decks with sunken fit pits or sitting spaces. If you want these things, you'll need a lot of space and some extra planning, but they're a great addition to any deck.
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    Plan for sun exposure. Do you want your deck to have full sun exposure? Always be shady? Get an even mix? What time of day do you want it to get sun or shade? You'll have to strategically place your deck and any objects that create shade (like a roof, pergola, or trees) very carefully.
    • Place a pole in the middle of your deck area and watch how the sun hits it over the course of the day. You can use the shadows it casts to get a vague idea of where you might need to place a roof.
    • You should leave the proper planning, however, up to your contractor, since a lot of math can be required.
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    Plan the access points. Will your deck have stairs leading out the the rest of the property? Will it need to meet up with a door or window on the side of your house? Planning these elements is important, since you'll need to adjust your design for each different kind of access point.
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    Decide on guard rails. Some decks are simply a platform and do not have anything along the sides allowing you to move seamlessly from your deck to your yard. However, some decks have guard rails. These can be crucial in keeping you and your family safe and may even be required by law, depending on where you live and the height of your deck.
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    Plan for utilities. Will you be putting a BBQ out on your deck? Mini kitchen? How about a hot tub? Lights along the rail posts? If you plan on needing a water, electrical, or gas supply on your deck, it's important to plan ahead on that, as these utilities will need to either be run from your house to the deck or may even need to be supplied from the street. This can be costly and may affect your design plans.
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    Get inspired. You can get inspired by other deck projects by looking at all sorts of helpful sites online. Pinterest, Google Images, and design sites like DIY Network all have great inspirational images to give you ideas that can be discussed with your contractor.

Part 2
Planning the Supports

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    Check with your local planning department. Cities and counties often have guidelines or requirements for how deck footings should be made. This is an excellent place to start when planning your deck.
    • Call your local city hall if you don't know how to contact the planning department.
    • It's important to call the planning department even if you don't need help planning the footing, because you will be required to have a permit and you'll want to know about any utility lines you may hit while digging the posts.
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    Plan on digging below the frost line. The post holes will generally need to be placed below the frost line, so plan on having the tools to do this, as well as know what the frost line is for your area.
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    Space the posts. Post spacing can vary, but a good happy medium is every 6' along the outside edges and roughly every 4' for the inside beams.
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    Space the joists. The joists should be spaced either every 12" or every 16". Only use 24" spacing if the wood you are using is very strong and the deck is not very high off the ground (< 3 feet).
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    Use smaller joists when possible. Standard joist sizes include 2x8, 2x10, and 2x12. However, the smaller the joist, the sturdier and less prone to bowing it will be.
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    Use thicker posts. Standard post options include 4x4s and 4x6s. Generally, the thicker it is, the more support it will provide, so choosing the thicker post is a better idea. Low decks, however, have less to worry about.
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    Reinforce areas that support extra weight. If you know you plan on adding a hot tub or other very heavy item to your deck, you may want to consider extra posts, mid posts, or trusses, as well as more joists, under the area where the heavy item will be located. This can prevent bowing and better support the extra weight.

Part 3
Using Planning Tools

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    Use Lowe's Deck Designer. The Lowe's Deck Designer will walk you through the process of choosing what size and style your deck will be. It will also calculate the spacing for posts and joists, make a basic building plan for you to use, and calculate the cost to build the deck.
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    Use Timbertech's designer tool. This is similar to the Lowe's tool but may offer different, and more biased results.
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    Use the Autodesk Home styler extension. If you want to figure out how much space your deck will need in order to fit a certain configuration of furniture, use this tool, which allows you to set the dimensions of the area and then fit furniture into it and arrange it however you like. It is available as a browser extension but also as a website.


    • Try putting some plants in there, like sunflowers.
  • Be sure and seal the deck with an exterior sealer. If you use a stain first that soaks into the wood, the wood will last even longer. The exterior sealer resists cracking and wear from the elements and your deck will look newer for many years.


  • The biggest mistake most people make is designing a deck that is too small. When they try to eat outside and put tables and chairs on it, they find there is no room!

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Categories: Home Improvements and Repairs