Extension Report

Baldwin County Extension Office

302A Byrne Street

Bay Minette, Al  36507

Beau Brodbeck

Regional Extension Agent

Forestry, Wildlife & Natural Resources

April 14, 2009

Why Plant a Tree on the West Side of Your Home?

Most of us enjoy the aesthetic beauty that urban trees provide; however, here is one more reason to think about planting a few trees in your yard.  A recent study by Dr. David Laband, an Auburn University Forest Economics Professor, suggested that power savings of 11 percent are possible if a house has just 17 percent heavy shade coverage. 

For years arborists, urban foresters and researchers have proclaimed the various benefits provided by trees, including electrical savings ranging anywhere from 3 percent to as much as 50 percent. “Over the years I have read statements that shade trees provide ecosystem services like reducing electricity consumption,” said Laband.  However, Laband explains that “the claims have never been measured very well, so we want to put a dollar amount on the impact of shade trees.” 

Laband’s research has been funded by a major USDA Forest Service Urban and Community Forestry Grant to provide solid figures to this illusive question.

Laband has conducted a study on 160 houses in the Auburn area over two years.  While on the surface this question may seem relatively simple, in reality, this research is very challenging because, as Laband explains, when considering the complexities of varying power usage, square footage, type of air conditioning, appliances, roofing, exterior material and other factors.  For example, the study, found that children under the age of 12 are major power consumers in the home.  They watch TV, play games and leave lights on.

“We are gathering real data from real living conditions,” Laband said. “This will make the analysis very complex, but it will be a very good analysis, rich with details. Each household will have its own lifestyle and characteristics that will be invaluable to the study.”  The research compared varying energy usages and factored in the shade coverage for each house.  Additionally, shade coverage was also considered during various parts of the day and year. 

Early morning sun is less intense than the hotter afternoon sun that causes summer days to rise in the high 90s.  After combining and considering all these factors, the study concluded that having trees on the west side of a house will reduce power bills by 11 percent with only 17 percent canopy coverage.  Depending on the percentage of urban forest canopy, this causes increases or decreases in energy usage.

Laband explained that when you consider one degree raise in your thermostat in summer it may translate into a savings of 3.3 percent on your power bill; in other words shade from trees could pay off.  In this way, ongoing research on the power savings and energy reduction capabilities of urban trees is now translating familiar concepts into dollar figures.  Laband plans to continue his research in this area by comparing two identical houses where he can more tightly control the amount of shade and measure with instrumentation. 

So, before the onset of summer, consider planting a few trees on the west side of your home.  Remember, during the winter months (December through mid-March), trees generally slow their growing process and become dormant.  Deciduous trees generally drop their leaves and the process by which trees produce sugars or photosynthesis becomes markedly slow.  The combination of weather and these biological processes make the cold winter months ideal for planting or transplanting trees. 

For additional information, please contact Beau Brodbeck at the Baldwin County Extension Office Bay Minette by email (brodbam@auburn.edu) or by phone at 937-7176.

Email address: brodbam@auburn.edu

Phone: 937-7176 or 943-5611, ext. 2222

The Alabama Cooperative Extension System (Alabama A&M and Auburn Universities) in cooperation with the U.S. Department of Agriculture is an equal opportunity educator and employer.