The front foyer of renowned textile designer Jack Lenor Larsen's East Hampton estate, Long House, serves as a year-round greenhouse and atrium. A glass ceiling is embedded along the spine of the peaked roof, about which Larsen says, “It’s remarkable that there aren’t more glass-ceilinged rooms. It didn’t cost more than a real ceiling, and it doesn’t lose or gain more heat, but if you can’t be outdoors, it’s very pleasant and the plants like it.” The beams and trusswork were made from Douglas fir in Minnesota. Photo by Jon Snyder. Photo by Jon Snyder.