According to CostHelper, contractors usually charge $35 to $45 per square foot for a basic garage, and up to $55 per square foot for a garage built with higher quality materials. For a basic single-car garage, that comes to between $9,240 and $11,880. A higher-end, single-car structure might cost as much as $14,520.ccording to Garaga, a single garage should be at least 12 feet wide by 22 feet long (264 square feet), and a double garage should be 18 feet wide by 22 feet long (396 square feet). Building bigger can bring the price up. Costhelper says an 850-square-foot garage with plenty of storage space could cost $38,000 or more.