How to Design a Family Room Addition

Check with your homeowners association if you have one. Planned communities, overseen by HOAs, may not allow any changes to your property's floor plan. If they allow changes, they must approve your plans before you proceed.

Know your building codes. Visit your local building department and determine the codes and regulations for your area. If you build an addition that isn't up to local codes, your city can tear down the addition--sometimes at your cost. When you complete your design, you can apply to the city for a permit to build the structure. When the structure is complete, it will be inspected by the city. A non-permitted structure can violate your homeowners insurance policy and make it more difficult to sell a home in the future. Any non-permitted structures must be declared when you sell your home.

Determine your available space. Measure the distance between the edge of the existing home's foundation and your property line. Building codes generally dictate how close you can build to your property line. In urban settings, it may be as little as 6 feet. In rural settings on larger properties, it could be a much larger distance--30 feet or more. Keep in mind that even if you can build relatively close to your property line, you may not want to. Do you need to move any vehicles or heavy equipment into your yard? Make sure to leave space. Also, you may not want your beautiful new family room to be too close to your neighbors, the street or an alley. If you don't have at least a 10-by-10 foot space available, it's probably not worth building an addition. Consider building vertically.

Design your foundation. If you're lucky enough to have a concrete patio in good repair to build on, you're ahead of the game. If you don't, you'll need to have a foundation dug and poured.

Think about doors and windows. When designing an addition, consider that every wall has some load-bearing supports that can't be moved. If you can enter the new addition through an existing door--or perhaps by removing a sliding glass door--you can avoid the issue. If your new entrance to the family room was your old exit to your backyard, design another exit door to your yard. You may be required to do this by code.

Consider heating and cooling. You'll want your new room to be as cozy as the rest of your home. If your home has an attic, it's relatively easy to add a vent to the new room. If your home has another kind of heating and cooling system, it may be more difficult. Also, your current system may not have the capacity to cool and heat any additional square footage.

Consult professionals to design and install your plumbing and electrical systems. Fire and flooding can destroy your entire home, not just your new addition.

Match your current exterior. Your addition should organically flow from your existing home. It should not block existing window views or create strange exterior dead spaces. The exterior of the addition should be made from the same materials as the rest of your home. If not, it will look cheaply done and detract from your home's value.

Imagine the room's use to determine custom details. Will the family room be used to watch TV? Read? Play games? When you have a good idea of what you would like to do in your room you can consider adding custom touches including flooring, lighting, built-in bookshelves or an entertainment center, sound system, wet bar and refrigerator.