There are two large contributing factors as to why the great majority of Vanderbilt students live on campus all four years. One is that the on-campus accommodations are pretty good. The second is that it is almost impossible to get off-campus permission. In fact, students are not even eligible for off-campus status until their senior year, and by that time, you’re pretty much institutionalized to the dorms.
If you do decide that you want to live off campus, there is a wealth of places to live within a short walk or drive from campus. On average, these places are much larger, have more amenities, and are much nicer. At the same time, they are a lot less expensive. The quality of what is available is in the "A" range, but Vanderbilt’s ability to accommodate students who want to live off campus is in the "D" range.