The current proposal, developed by McKinstry, will be implemented in the following sequence: [see diagram at beginning of the drawings on previous page]
The first step will be to construct new main risers in the unused space in the trash rooms. This will involve core-drilling through the concrete floor slabs. On the lower floors there will be two risers, one that serves the 7th floor and below, the second riser that serves the 8th floor and above.
Once the risers are in place, lateral distribution loops will be placed in the hollow ceiling spaces of three floors: 7, 15 and 23.