Here are some Key facts taken from the ASLA’s Report
- Roof produced a 10 percent decrease in building energy use over the winter months.
- The temperature on the green roof on the hottest summer days can be as much as 59 degrees cooler than conventional roofs on neighboring buildings.
- During a 10–month monitoring period, ASLA’s green roof prevented 27,500 gallons of stormwater — nearly 78 percent of all precipitation hitting the roof — from flowing into D.C.’s overburdened sewer and stormwater system.
- Water quality testing shows that the water runoff contains fewer pollutants than typical water runoff. Most significantly, the roof is reducing the amount of nitrogen entering the watershed.
written by Nancy Somerville, Hon. ASLA and Chistopher Counts, ASLA