While green homes often sport all manner of technical solutions to keep them optimized and efficient, the landscaping can have a significant effect on the building and its energy use. Site orientation and landscape can also be powerful tools to control the energy needs of a building. While it’s not practical to reorient most homes, in many cases you can still make improvements by planting trees.
Trees offer numerous benefits beyond their contribution to cooling. If the warming weather has you thinking about landscaping, give some consideration to using trees to boost your home’s comfort through the summer. Spring is prime tree planting season, particularly for more northern latitudes, so now is a good time to consider putting in a new tree or two.
Even with an air conditioned house, it makes sense to plant shade trees in order to reduce the solar gain on the house. Windows, in particular, will benefit greatly from being shaded. But keeping the siding material in shade means less thermal gain to the wall, and that also translates into less demand for cooling and lower energy bills. Shading can also mean that natural cooling with passive ventilation instead of mechanical conditioning can be used more often, which also helps lower energy demand.
Individual results will vary with many factors, but generally speaking, the southwest is the most important orientation to provide shade cover for, since it is afternoon peaks that are typically the hottest part of the day.
There are lots of mechanical systems that can be added to a house to keep it comfortable, and we love seeing new and useful technologies for green buildings. But sometimes it is not the technical solution but just the simple measures that make the most sense. And trees offer another benefit. Unlike many other building improvements that slowly degrade over time, the benefit from a tree will increase over time as the tree matures and increases the good that it does for the house that it shades.
In addition to cooling, trees (particularly evergreens) can also serve as windbreaks to shelter homes in the winter time. But, whether for summer shading or to serve as a windbreak, now is a good time to plant that tree.