On first glance, it seems the roof of the HealthRidge Fitness Center is floating. As with most tricks, figuring out how it's done is easy when you look more closely.

As if by magic, the roof of the HealthRidge Fitness Center appears to float above the end walls, the generous glass on the exterior offering so many views inside that nighttime visitors to the grounds of Corporate Ridge Office Park in Olathe, Kan., might wonder what holds the building up. As with most tricks, figuring out how it's done is easy if you watch closely. The weight-bearing interior steel structure was well hidden by Opus Architects & Engineers Inc. of Minnetonka, Minn.; the firm camouflaged posts by lining them up with window mullions and set beams just under the roofline along the building's sides. The effect is heightened by the facility's variety of window openings, an attempt to bring a random, playful quality to the facility while maximizing views out to the pastoral setting.

So, what seems like an engineering feat is actually the result of a purely aesthetic decision, and advances in diffuse, low-E glass (which mitigates the problems of heat gain and glare) allow architects to take the idea even further. A wave of the wand, and they could make all the solid parts of the walls vanish.