True to the World Heritage inscription that Robie House is part of, it exhibits discernible elements of “organic architecture” and a number of techniques and solutions that mark Frank Lloyd Wright as one of the foremost innovators of the 20th century in his field. And yet in visual terms, it is a bit underwhelming once you step inside. There are lovely partially stained-glass windows throughout, notable built-in features doubling as decorative elements, and examples of impressive masonry echoing the exterior, but the relative emptiness of the house mutes the impression quite a bit.
If you are a student of architecture, especially its modern history, you will certainly get value out of your visit. The guide provides a lot of context, historical nuggets, and rationale behind architectural decisions to make the trip worthwhile. Those who expect visual impact may be disappointed. Other Wright's buildings, such as Guggenheim and Fallingwater are degrees of magnitude more impressive. Even Kentuck Knob, which is not part of the WH inscription, retains a bigger visual impression in my memory.
Guided tours run throughout the day, starting every half hour and lasting about 45 minutes. Advanced reservations are required these days.