In a passive solar house, which direction should large windows face?

In passive solar design, the orientation of windows is crucial for optimizing natural lighting and heat gain. Large windows should ideally face south in the Northern Hemisphere, including California, to capture the most sunlight throughout the day. This orientation allows for maximum solar heat gain in winter, when the sun is lower in the sky, while minimizing exposure during the summer months through strategic shading techniques.

By having large windows oriented to the south, the house benefits from passive solar heating, which helps reduce reliance on artificial heating sources and can lead to increased energy efficiency. The sun's path in the sky is lower in winter and higher in summer, so south-facing windows take advantage of the winter sun while reducing heat intake in the warmer months, resulting in a comfortable indoor environment year-round.

Other orientations, such as north, east, or west, do not provide the same level of effective solar gain and energy efficiency in a passive solar design. Thus, south-facing windows are a fundamental aspect of constructing an energy-efficient passive solar house.