OAC | News

May 15, 2005 - Building Envelope Design Enhances Cobb Building Redevelopment

OAC is providing building envelope design services for the redeveloped Cobb Building, to be occupied in fall 2006. The original building envelope construction has performed well. The renovation will include tie-in to a new building core and the addition of terraces on the second and eleventh floors. Existing wood windows will be restored and/or replaced. Wall cross-sections and existing finishes will remain the same. Waterproofing will utilize vintage-style details and copper flashings. Some materials will be reused and others will require replacement.

The new waterproofing schemes are being designed to fit into the existing architecture, maintaining its aesthetic appeal, while performing well. The roof will be waterproofed and tie old structures to new structures, including the 11th floor terrace and a new penthouse, which will be waterproofed using copper flashings. Design considerations include waterproofing details at seismic expansion joints.

Constructed in 1910, the historic 11-story Cobb Building was the first dedicated medical-dental building in the Western U.S., providing office space for more than 200 doctors and dentists. The building is part of the Metropolitan Tract owned by the University of Washington, where the University was located until 1895, and includes the area bordered by Union and Seneca streets and Third and Sixth avenues.

By 2003, the building contained 75,000 square feet of office space and was 19 percent vacant. The building's "L" shape, interior columns, and vintage configuration were not conducive to modern office space, but would be well-suited for residential space.

After the Nisqually earthquake highlighted the need for seismic and system upgrades, owner Unico Properties began planning for conversion. The redevelopment is targeting LEED™ Silver certification and will feature 90 high-end apartments, 810 sq. ft. in size, with views of downtown Seattle and Puget Sound. Street-level retail space will be renovated as well. The renovation will preserve detailed stonework, including Indian-head carvings at the top of the building.

OAC is working with GGLO to coordinate design elements. The project is being constructed under a negotiated contract, where general contractor Lease Crutcher Lewis is involved with the design team and providing preconstruction services.