One of the most powerful aspects of Louis I. Kahn's architectural space is his handling of natural light. Kahn believed that architecture began with the "making of a room," and that "a room is not a room without natural light." Throughout his career he endeavored to bring his interiors to light in the most imaginative ways. Kahn used passionate light and functional light, glaring light and indirect light, warm light and cold light, each working differently in his architecture. This book presents the best introduction to Kahn's ideas about light in architecture. Using drawings, photographs, analytical diagrams, and critical descriptions, author Urs Buttiker investigates, in chronological order, Kahn's lighting solutions in 49 of his best-known projects. The book contains a wealth of technical details covering the entire spectrum of light modulation employed by Kahn throughout his career: the ceiling-framed window, the lookout slot, the keyhole window, many variations of brise-soleil, sliding window shutters, double space envelopes, the light cylinder, light ports, and an endless variety of skylights.