Cooling off with Trees Sunlight, or solar energy, hits the roof and comes through the windows, accounting for most of the heat gain inside a house. Therefore, the most important places to use shading are the roof and windows. Energy conservation measures that block the sun before it strikes the roof or windows are the most effective. Trees and other plants that provide shade are your best long-term investment for reducing cooling costs. Trees and landscaping are the most effective measures for blocking solar heat.
Trees are also a good investment.
Additionally, the more shade you have, the more effectively you can use natural ventilation. Shade makes the air around the house cooler and it prevents solar heat from building up indoors. Trees should be planted on the southeast and west sides of your home for the maximum shading effect. Not only will trees help lower your energy costs over the years, but they'll make your home a greener and more beautiful place to live.