When we talk about landscaping the site, most professionals will consider a couple aspects: beauty and water conservation. A good architect will see the site holistically from the beginning. Besides beauty and water conservation, an architect will investigate how to use new and existing landscaping as a passive design strategy to reduce energy loads on a proposed building.
Landscaping as a passive design strategy is most often used as a “catch up” method – especially in the high plains here in Colorado. It is a method used after-the-fact when heating loads are discovered to be to extreme for the construction and a homeowner is desperate. This is a valid solution to an existing problem. However, it is imperative to note that passive design strategies are most effective when holistically integrated into the site and building planning in the earliest stages of design.
During site analysis, Colorado architects strategize how to minimize the effect of cold winter winds in an “externally loaded building” or home. Using new or existing landscaping intuitively can reduce wind velocity. Reducing wind velocity on your building means you also reduce the energy load. In order for the home to be protected by neighboring trees, the house needs to be located within a distance of 5 times the tree height.
Many times, due to site constraints, a deep row of trees (as demonstrated above) is not possible. Sometimes, only a single row of trees may be feasible. A single row of trees has the ability to reduce wind velocity by 35% if the building is located within 5 times the height of the trees.
Maybe the site is very small. In this case, all is not lost. A single row of very dense evergreen trees planted as close to a home as possible can reduce a bone-chilling winter wind by up to 60%. This will make a big impact on your energy usage.
In warmer climates, landscaping is used to minimize energy usage. Using deciduous trees on the south side of any home can provide much needed shade in the warm summer months and allow solar heat gain in the cold winter months after the leaves have fallen. The only caveat to this would be any building relying on the use of solar panels.
The architect uses new and existing landscape as a passive design strategy in the beginning stages of site planning (before a building is even conceived) to bring you the most value.
Until next time!