A standard one-car garage ranges in size from 12 by 20 feet to 14 by 22 feet, according to Western Construction. The size can go up to 16 by 22 feet on lots that accommodate the extra space.
A depth of 22 feet is enough to accommodate most full-size trucks, vans and sport utility vehicles. A garage that is 12 or 14 feet wide usually includes a door that is 9 feet wide and 7 feet high, according to Horizon Structures. Homeowners who need extra storage can build a garage that extends up to a second story, adding a floor and a staircase to create a garage attic.