Select a tree that can be planted within twenty feet of the window and will grow at least ten feet taller than the window. When space permits, use as many trees as needed to create a continuous planting along all major west and east facing windows. Austin Utilities Tree Program Guidelines Select a tree that will grow as big as growing space permits. Remember, a tree needs space for both branches and roots. Since the most beneficial locations for shade trees are close to the east and west sides of buildings, the best trees will be strong, resisting disease and pests and damage from storms.
Many species are inherently more appropriate for energy conservation plantings.
Avoid trees south of windows Contrary to intuition, the worst place to have a tree from an energy-saving perspective is out in the yard south of a home. In summer when the sun is high in the sky at midday, the shadow of a tree falls directly under the tree and entirely misses a home to its north. In winter, however, the shadow of the same tree will fall on the house throughout most of the day. To avoid shading south windows, any trees south of the home should be located at least twice their mature height away from the house. Planting shade trees due west of west-facing windows.