Never trust anyone over 30. Or so the saying went. Of course, the youngsters who coined this phrase have since learned a thing or two about the wisdom that comes with age.

When this magazine began compiling data to reflect the industrial strength of our profession, we knew the numbers would back up our claim that good design is good business. In fact, a 500 percent increase in total project square footage has translated into some serious longevity for the biggest players. Since we inaugurated the Interior Design Giants list in 1978, 10 of the current top 200 have consistently appeared: Gensler, HOK, HBA/Hirsch Bedner Associates, Pavlik Design Team, Daroff Design + DDI Architects, KlingStubbins, Swanke Hayden Connell Architects, Hendrick, Ford & Earl Associates, and Design Collective. Nine Giants have celebrated centennials, while 18 were born at roughly the same time as the Giants list.

Here, we look back at some of the innovative projects that have made corporate titans take pause and consider exactly what design can contribute to the bottom line. Considering the past makes us realize how much is possible in the future. Especially now that we know life begins at 30.