12' Wide Garage Plans Find the internet’s best collection of 12' wide garage plans that are perfect for your needs by Behm Design. This is the smallest 2 foot increment width dimension possible for a one car garage. The minimum industry standard single car garage door width is about 8 feet. The IRC building code requires minimum of 1'-4" of wall length adjacent to garage door on both sides. So about 10'-10" in actual minimum width. Also, with an average width automobile, its door swing space must be considered, as well. So if you consider less than 12' overall garage width there may be problems using it as intended. Even 12' is tight for some vehicles. That is why Behm Design also offers 14' width garage plans. Before committing to building any particular garage we recommend checking the dimensions of your vehicle(s) to know what you really need. Considering depth, as well, there are many possibilities in out garage plans inventory.