Expert: Ted Barnhill (Principal, Design45 LLC) - 7/12/2008

Question
I am in need of efficiently creating closet space in a small back "bedroom" and cannot sacrifice floor space. I had an idea of creating a 2.5x11 closet extension (separated into 2-closets) as a lean-to on the back exterior wall of my home. I believe these are called saddlebag extensions. My question is: How should I attach it to the house. How can I make the extension sort of floating, attached to wall but without ground support? The room is on a crawl block foundation.

Answer
Keith,

What you are proposing is called a "cantilevered" addition, meaning that it overhangs your existing foundation without any new foundation required.  Whether this is economical in your instance depends on the direction and depth of your existing floor joists, and the capacity of your existing foundation to take on additional load.  If your floor joists are perpendicular to the wall you'd like to "bump out," then you may be able to sister joists on to them which extend out to form your new floor.  If, on the other hand, your floor joists are parallel to the wall in question, it is probably cheaper to excavate and add a new foundation for your addition.  Your designer, engineer, or builder will be able to verify the existing joists and foundation and design the best solution.

If you have any additional question or follow-ups, feel free to post them.  -Ted