Slate has an interesting photo essay on MegaChurches. From the comments on Willow Creek:
The sprawling complex, on an attractively landscaped 155-acre site, includes not only two sanctuaries but also a gymnasium that serves as an activity center, a bookstore, a food court, and a cappuccino bar. Goss/Pasma Architects of Evanston, Ill., did not include any traditional religious symbols on the exterior: no steeples or spires, no bell towers, no pointed arches, not even a crucifix. It doesn’t look like a place of worship, but what does it look like? A performing-arts center, a community college, a corporate headquarters?
…most contemporary megachurches are resolutely secular in design. The 4,550-seat sanctuary—it’s actually called the Main Auditorium—of Willow Creek appears to have good sightlines, excellent audiovisual facilities, and comfortably wide aisles for moving around in. But inspiring it’s not. It’s the architectural equivalent of the three-piece business suit that most nondenominational pastors favor.
You have to love the fact that there is absolutely nothing offensive about the three featured “evangelical” church buildings.