Since the well before the end of the Cold War in 1991, there has been a greatly reduced interest in building and/or maintaining bomb shelters in most countries unless there is active strife still active, at least until fairly recently. There has been a renewed interest, particularly after the September 11th attacks on the United States, for an updated version of the backyard bomb shelter.
Some modern versions of the classic storm cellar can be purchased to install under your garage floor either at the time of building or aftermarket. They are usually steel with a sliding door on top that allows you to continue using your garage for parking in. They tend to be rather close quarters inside.