That's true for aluminum tanks, but it's not true for Carbon Fiber tanks, which SpaceX is rumored to be considering for the BFR. Having a larger diameter first stage has a bunch of advantages: It would make the rocket shorter, which would make it easier to work with.
Bigger Is Better. Garages are used as workshops, parking spots, laundry rooms and for storing all those things you wish you would have never bought. With so many uses, it's important to allow plenty of space. Two-car garages are typically at least 18 feet wide by 22 feet deep. This allows room for two 9-foot garage doors and for cars to pull in completely. Of course, if you don't plan on parking a car in your garage, you may opt for a smaller structure.
Well Then Ask Yourself What Size Are Double Garage Doors? The size chart of a double garage door measures out to 12 x 7 feet, 14 x 7 feet and 16 x 7 feet. This is designed for more than one vehicle and for bigger vehicles to fit inside your garage as well. Manufacturers offer this length and the length presented earlier for single and double car garage doors.