Primer

How the Sun's Path Can Inform Design

Designing a building with the sun in mind can help reduce both heating and cooling loads.

Sun shining into a building provides free heat and natural light. It can also create glare and, when the heat isn’t needed, discomfort and added demand for cooling. Using sunlight when it’s needed and deflecting its power when it’s not are two of the most important tasks in building design.

The sun rises in the east and sets in the west. Because the earth rotates on an axis that is tilted, however, the sun doesn’t stay exactly in the east or west. In summer, it rises north of east, travels high across the southern sky, and sets north of west. In winter, it rises south of east, travels low across the southern sky, and sets south of west. How high it gets in the summer and how low in the winter depend on how far you are from the Equator. (If you’re reading this in the Southern Hemisphere, north and south are reversed.)

Published March 31, 2008