If you live in a cold climate and you have a middle class home and have a garage, so your home sale value would be rise just because it has a garage. If your garage can accommodate one car then the selling price of your home will raise $ 30,000. But if only one, then you are entitled to an additional $ 20,000. Usually two-car garage has a width of 20 feet. While for a single car garage has a minimum width of 10 feet. In the garage you can add circuits, plumbing, and electrical outlets. Other than that you have to install on your garage the roof construction to support a water ducts. Build the water ducts structures could increasing the costs. But if you do that so you can have the extra room to perform various activities. Exterior Design.