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.
1 Accomplished do-it-yourselfers can cut costs considerably; materials for a single-car garage with a door but no windows start at $3,000-$4,000, depending on the size and style. dont know how the author figures a two car garage is 380 square feet, when most cars require a 24 x 24 foot garage which is 576 square feet, and that just gives you enough room to open the doors of the car.