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.
A single car driveway width should be 10' wide, anything less. than 10 feet will be too narrow to drive or park on comfortably.12' is often used for added comfort and assuring to get out of your vehicle without stepping on the lawn or landscape. two-car driveway can comfortably fit two cars, side by side. The  standard double car driveway is between 18 and 20 feet wide by 18  to 20 feet long. 6 people found this useful. Edit.