Columbia School of General Studies doesn’t have any dorms. Most NYC universities don’t — the real estate is too expensive.
There are several dorms on the Columbia campus. It has been many years since I attended graduate school there, but two come to mind - John Jay and Alexander Hamilton, both dorms named after former students.
At the time, in the late 60s, Columbia College was for full time male students, Barnard was for full time female students and the school of General Studies was for those who wanted to attend Columbia on a part time basis as well as full time. It made a big difference whether one attended Columbia College as opposed to GS. Those attending CC looked down their noses at those attending GS. Plus, it was much easier to gain entrance to GS.