The solar envelope , first conceived and tested at the University of Southern California, is a container to regulate development within limits derived from the sun's relative motion. Buildings within this container will not shadow their surroundings during critical periods of the day. The envelope is therefore defined by the passage of time as well as by the constraints of property. The solar envelope calls for a design strategy based on natural rhythms. The potential exists to conceive of architecture in other than static terms.
Sunlight can add a dimension of time to conceptions of form and space.