This course explores material and optical design strategies for thermal management of buildings. In the first part of the course, we cover fundamental aspects of thermal radiation and light-matter interactions in built and natural environments. The second part covers traditional and emerging materials and strategies for radiative thermoregulation of buildings. Specific topics include traditional designs such as cool-roof films and low-E coatings, emerging materials like radiative coolers, and adaptive coolers/heaters, and their impact within buildings and the broader environment.