If you’ve been following our blog, you probably know that trees and vegetation are most useful as a mitigation strategy when planted in strategic locations around buildings. But did you know that researchers have found that planting deciduous species in specific locations of certain areas can provide special benefits? For instance, planting trees to the west are most effective for cooling a building, especially if they shade windows and part of the building’s roof. The shading of the east side of the structure can also reduce air conditioning demand.
There are several more ways to think about where to plant trees and shrubs in urban environments. We will offer several tips in the below paragraphs on where you should be thinking about planting your trees and vegetation.
Planting trees to the south can lower summertime energy demand, in places north of the equator. Although this must be done carefully. Depending on the trees, the building’s height and distance between the trees and the building can be detrimental to an energy efficient strategy. For example, if they block useful solar energy in the winter, when the sun is low in the sky, then they will not allow solar rays to enter the house, providing a natural heating element. Likewise, in the summer, tall trees should be planted on the west side of the structure, blocking most of the daytime solar rays.
As mentioned in our previous post on reducing urban heat islands, shading pavement in parking lots and on streets can be an effective way to help cool a community. Not sure where to plant? Start by addressing the perimeters and the medians. Strategically placed shade trees also can benefit playgrounds, schoolyards, ball fields, and similar open spaces.
You’ll be glad to know that trees are not your only option. There are many areas where trees either do not fit or grow too slowly to be effective over the shorter, in which case vines may work better. Vines are great because they use less soil and space and grow very quickly. Typically, vines are best grown on the west side of the building, where they can grab the most solar rays as possible. Vines will shade the exterior wall and reduce heat inside of the building. The vines will also provide some air cooling benefits through evapotranspiration.