This cabinet is 36" wide x 21" high (exterior dimensions). Sizing for an appliance garage, depends on what you plan to store inside (and the space required), and the type of doors used. Retractable doors on each side, like this one, will take approx. 3+" off the usable interior width, whereas, a lift up door would be different. There are many operating hardware options, each affecting the interior space differently. Your cabinet fabricator should advise you on size, once the cubic interior dimensions are determined. Good luck on your project!