In the aLIGO era, folks working at the upper level of BSCs have garbed on the E-module and then entered the Chamber Cleanroom. With the cleanrooms, E-module, etc. in the BSC10 configuration, there is no easy/acceptable way to access the E-module. If you need to do ANY cleanroom work (upper OR lower level),turn right as you come through the Change Room man-door, find the Lower Level Garbing/Staging Room and "bunny-up" there. If you need to work on the upper level or at the spool, pass through the Chamber Cleanroom to access the Spiral Staircase or the CPB Cleanroom. Avoid walking through the Test Stand Cleanroom. If you want to access the far side of the beamtube, there is no need to garb up: just turn left as you come through the man-door and follow the wall around.