Most rooms of BU on-campus dorm/apartment are separated by the wood, including 580 Commonwealth ave (dorm for graduate students). However, the floor of graduate dorm is made of cement with carpet....
If you will live at 580 Comm, you can move in later....even during the weekend or at night while the office of the rental property is closed. There will be a student RA (resident assistant) on duty, he/she can give you the key and let you in.
The quality of 580 Comm is really good although it's a little expensive. :-( It's on campus and very close to most buildings/departments, especially MBA
For some people applying for 580 Comm, sometimes you will not be able to get notice until mid-July since people who currently live at 580 comm are only required to report their intent to continue to live at 580 Comm by the end of June. So the office will know how many rooms will be available for the following year around early July. Anyway.. good luck. :-)