Scoring Big in LEED: Landscape

On July 19, 2010, the Leadership in Energy and Environmental Design, better known as LEED, adjusted their point system.  Instead of the 69 previous total points, the scale now reaches 100 increasing the points required for minimum certification (40), silver (50), gold (60) and platinum (80.)  Of the most notable changes to the point scale, the Water Efficiency category doubled in point potential from 5 to 10 points, catapulting it to 10% of total possible points.  On top of those points, landscape irrigation is also counted in the Sustainable Site category, with two points for Stormwater Management and two points for Heat Island Reduction.  What does this mean?  More than ever before landscaping can effect a LEED project’s certification status.  It even has the potential to make or break whether a project reaches Gold or Platinum status.

Of the Water Efficiency points, landscaping is directly tied to four of them (up from two points).  Here, the name of the game is water-use reduction.  This can be achieved in a combination of ways.  For one, employing native plant species or drought tolerant plants is an immediate way to cut water needs without employing any technology.  Plants such as the California Poppy, Mariposa Lilly, and Desert Willow provide form and function.  Where irrigation is required, high efficiency technology such as drip irrigation will score LEED points by reducing water use 30 to 50 percent.  Furthermore, smart irrigation controllers can round off the total water savvy package since they shut off during times that water is not needed, such as a cool or rainy day.

Being able to use captured rainwater or greywater sources for irrigation purposes is also a crucial component to the LEED score system.  It’s important to make sure your landscaper has experience tapping into existing waterlines, which can be tricky due to location of the controllers.  Without this your system may not pass upon inspection.

Another way to rack up those landscaping points is to integrate living walls with the structure.  Living walls are nothing more than a wall covered in vegetation that is rooted to the ground.  They are typically created out of pre-vegetated or fabric panels containing plastic containers, or geotextiles, as well as irrigation systems in which vegetation attaches to the wall or supporting structure.  A commonly used living wall is green screen.  These systems can help a building attain an added level of energy efficiency.  Just as a layer of hair can help heat and cool a living being, living walls provide additional insulation, thereby decreasing a building’s heating and cooling requirements.  As a result, these walls are best applied on the east and west ends of buildings to counteract the sun’s rays during the warm summer months.

Similar to living walls, green roofs are another way to build LEED points.  The sheer existence of them will help build Heat Island Reduction points as long as they make up 50% of the roof.  But with this size they are not only able to reduce roof temperatures, but can also prevent stormwater runoff- one of the keys to gaining points for stormwater management.  The combination of drought tolerant plants and pervious paving can retain up to two inches of rain.  Plus, the landscapers can tap into greywater systems to help irrigate the roof with non potable water.  All of this can build LEED points.

Lastly, the simplest way to build LEED points: plant more trees.  Especially over paved and impervious surfaces, such as parking lots.  The amount of shade provided by the trees all add up to LEED points.  Some shrubs and other vegetated surfaces, like the green screen living walls, will work too.

With this increase in point impact, it is important to work with a landscape contractor that is proficient in these green techniques and/or has had similar past experience.  Ask your contractor to provide references of past projects they’ve worked on that might apply to your upcoming project.