From the beginning of architectural history, climate has been a major controlling force in building design. A building’s envelope must keep out the elements and minimize great temperature changes as well as admit light. Massive masonry walls were employed as thermal storage to alleviate excessive temperature swings. The thickness of these thermal barriers affected lighting conditions within the structure. Sunshine was prevented from reaching the interior. Instead, the daylight was softened and diffused as it reflected and bounced along the fenestration’s thick walls. Not only was the skin used for thermal control, it also provided illumination for the interior. Daylight was the primary method of illumination which was supplemented with candles and oil lamps. Because the skin of a building was the only mediator between the interior and exterior climates, all perforations had to be carefully considered. Buildings were designed to make use of the daylight. Activities which needed illumination were limited to daytime hours. Rooms were placed along the exterior walls of buildings to make the most of the daylight illumination. Building depth was restricted by how deeply daylight could penetrate into a room. Interior courtyards were implemented to illuminate interior spaces that could not be accommodated by exterior windows. People who wanted to remain within the confines of their building but needed large quantities of light to complete their various tasks would gather here. The courtyards lent a sense of community to its inhabitants. People were able to communicate with one another both verbally and visually. Daylight did more than illuminate interiors. It provided a constantly changing visual atmosphere. The light which passed through the fenestrations reflected the ever-changing movements of the sun and clouds. Without looking out a window, one could sense the moods of the day as well as the passage of time, the atmosphere within was always changing. With the advent of the Industrial Revolution, building design was changed. Climate could be ignored in building design. Inventions such as electric lighting and forced air circulation replaced windows. Rooms no longer depended on their proximity to the exterior face for illumination. Large workspaces could be partitioned into small individual offices. With smaller space and individual offices, employees no longer had direct access to one another. The uniform electric lighting produced a static atmosphere. The visual atmosphere and the sense of community that came from courtyard design was lost. Was it really necessary to lose the subtle qualities produced by ancient building methods just to have modern amenities? Was there not some way to use technology to enhance those ancient qualities? At a time when most architects shunned the old ways to embrace the new technology, three architects stood out because they chose to incorporate the new building methods with the old. The three architects were Frank Lloyd Wright, Louis Kahn and Alvar Aalto. These men were able to design buildings based on the climatic conditions of a site and integrate those designs with twentieth century technology. / Master of Architecture