Most innovative nonresidential retrofit project

101 North Wacker Drive, Chicago / Curtainwall Services Inc.
This is a photo taken in the vacant space where the original mockup was constructed by Curtainwall Services. The mockup was done purely on spec by Curtainwall Services, with no assurance of getting the job.
In this photo, the striking difference when viewed from the interior is clearly visible, allowing 50 percent more natural daylight into the interior and creating a true floor-to-ceiling aesthetic where one did not exist before. In this photo, you can see a short stub of drywall with the base board heaters still attached and operable. The dismantlement of the interior drywall finishes shown in the before photo was done in such a way that the heaters remained in place and in operation throughout the process. New brake formed and painted aluminum sill closure components designed by Curtainwall Services were installed to cap the raw space and create a pleasing and clean-looking finished appearance.

The 101 North Wacker Drive Building is a 23-story commercial building located in the Chicago central business district. Completed in 1981, it is clad in a simple stick-built curtain wall system manufactured by Starline Industries. The floor plates are 180 feet by 150 feet, featuring a 30-foot column bay and 5-foot mullion spacing. The entire glazed area of the façade—as originally constructed— consisted of four equal-sized window openings per floor, two 36-inch-tall by 60-inch-wide vision units, and two identically sized spandrel units. Interior finishes consisted of sheetrock over light-gauge metal framing to cover the lower spandrel glass unit on the interior, with perimeter baseboard electrical heaters attached thereto. Each floor was built with 6 feet of daylight opening above the interior sill.

Curtainwall Services Inc., Elmhurst, Ill., received an inquiry from representatives of Hines, the Houston-based global real estate company, asking if the interior drywall finishes could be
removed, and the monolithic spandrel glass panel replaced with matching
insulating glass units, thereby converting this somewhat dated interior to true floor-to-ceiling glazing. A cursory review of the shop drawings confirmed the constructability of the proposed initiative.

Initially, ownership selected a vacant space on the 11th floor, in the southwest corner, to perform a two-bay mockup of the proposed retrofit. In the end, Curtainwall Services Inc. was retained to perform a complete turnkey design build package. The ultimate scope of work
included the removal and replacement of 2,662 spandrel units and the installation of new IG units and gaskets. Viracon was instrumental in helping the Hines/Curtainwall Services
team select the two types of replacement glass required to complete this makeover.
Viracon's reflective coated glass, VA1-13 insulating glass HS/FT, was used on the south and west elevations. Its tinted low-E glass, VE-85 insulating glass HS/FT, was used on the east and north elevations.

More than 80 percent of this work was performed at night in occupied offices. Each night, one column bay (or six units) was dismantled and re-glazed, and custom designed brake formed and painted metal sill closures were installed. "Without a doubt, the single greatest challenge—throughout the nearly 22 months of continuous activity in winter, summer, rain and snow—was that the bay that had been scheduled that night had to be completed and returned to full functionality by 7 a.m. the next morning," says James Whaley, vice president and general manager for Curtainwall Services.