Cornerstone served as the Building Envelope Consultant for the Pier 66 Grand Staircase Replacement, supporting the Port of Seattle with enclosure strategies focused on durability, performance, and sustainability. Our scope included the design and oversight of the waterproofing system, with detailing coordinated to ensure continuity of air and water barriers across critical transition points. A key focus of this project was nighttime safety and visibility, ensuring the staircase functions and remains accessible well after natural light is gone. During construction, Cornerstone reviewed submittals, field detailing, and installation practices to identify and address potential deficiencies early, reducing rework and supporting long-term enclosure performance. Equally notable was our commitment to sustainable reuse. We supported the careful removal, storage, and reinstallation of approximately 2,250 cubic feet of extruded insulation, diverting material from the landfill, preserving thermal performance, and avoiding an estimated 1 to 2 metric tons of CO₂ emissions. This effort reflects our belief that sustainable reuse should be a standard consideration on every project, not just those with defined sustainability goals.