REMOVE EXISTING ACCESS HATCH AT ROOF LEVEL OF STAIR S2 AT SEATTLE CHILDRENS BELLEVUE CLINIC AND SURGERY CENTER. CONSTRUCT NEW ROOFTOP PENTHOUSE TO ENCLOSE TOP OF STAIR AND ADJACENT LANDING, WITH EGRESS DOOR FROM ROOFTOP. AUGMENT EXISTING LIGHTING, ELECTRICAL, HVAC, AND FIRE SUPPRESSION SYSTEMS TO SUPPORT NEW CONSTRUCTION.