A 1965 cast-in-place concrete office building in Bala Cynwyd, Pa., was showing its age. The tenants were hot in the summer and cold in the winter, and the 345,000 square-foot building needed an update inside and out to address occupant comfort and energy efficiency. Renovation to an existing concrete structure is a challenge, even more-so while it is fully occupied. Tishman Speyer, the building owners, called in McGillin Architecture Inc. for the project.
The original plan was to replace the original single-glazed ribbon windows, build a small entrance addition, and refresh the exterior with new paint. Replacing the windows seemed like a relatively simple task, but early investigations found that the cast-in-place concrete on the upper four stories was not suitable to support modern window systems. The team quickly determined that a new design approach was needed.