What is the coolest part of the building in summer?

In terms of sunlight exposure and the heat that different faces of a building absorb during the summer, the east side of a building tends to be the coolest during the late afternoon and evening. This is primarily because the sun rises in the east and the morning sun is less intense than the afternoon sun, which heats the southern and western sides of buildings.

As the day progresses, the east side receives direct sunlight for a shorter duration compared to the south and west sides. By late afternoon, the sun is positioned more to the west, meaning the south and west façades will be absorbing more heat while the east side starts to cool down. Additionally, if the building has any vegetation or shade structures on the east side, that can further reduce the temperature in that area.

This aspect of building orientation is crucial in landscaping and architectural design to promote energy efficiency and comfort. Understanding how different sides of a building interact with sunlight can help in making informed decisions for planting and creating shade, which contribute to overall energy savings and a more pleasant microclimate around the building.