Walls that separate a sole-occupancy unit from a plant room, lift shaft, corridor, stair, foyer or similar public area, require a minimum sound rating of Rw 50. There is no Ctr adjustment. See diagrams 6.3 and 6.4 for details.

Walls that separate a sole-occupancy unit from a plant room or lift shaft are required to be of discontinuous construction. Eg: the independent stud or Continuous Stud-sheeting systems.