Principal Financial HQ

OPN Architects has worked with Principal Financial Group since 2013 on a five-year, roughly $400 million renovation of its downtown Des Moines campus. The centerpiece is 711 High Street, where the architects removed the core of the seven-story building and raised the roof to enclose the original exterior courtyard under a single skylit atrium, connecting three buildings and bringing the campus's skywalks to one level. The building reopened in June 2017. Exposed steel trusses and a custom programmable electrochromic skylight manage daylight across the full height of the space, while black-framed glass conference rooms cantilever into the atrium from the surrounding floors.

Bendheim's low-iron channel glass wraps walls, balconies, and stair railings throughout the atrium, held off the surface behind it so light and reflection move across the glass as a visitor walks past. The installation adapted Bendheim's Wall-F rainscreen clip system, normally an exterior product, for interior use - reportedly the first large-scale interior application of that kind of system in the United States.