Report: Green Building Water Efficiency Strategies

This report, from researchers at Virginia Tech, describes some aspects of project compliance paths for projects earning water efficiency credits under LEED for New Construction v2.2. A stratified random sample was taken of all non-confidential certified projects earning these credits under this version of the rating system, and compliance forms for Water Efficiency credits 1, 2, and 3 were analyzed. Usage rates for water efficient landscaping, non-potable water sources, on-site wastewater treatment, and selection of plumbing fixtures and tap fittings were calculated.

It was found that for WEc1: Water Efficient Landscaping, projects most often avoid permanent irrigation altogether. Rainwater was the most common non-potable water source for those that selected that compliance path. Wastewater reduction was selected over on-site treatment, and high efficiency toilets and non-water urinals were most often used to meet the high reduction necessary to earn the WEc2: Innovative Wastewater credit. Dual flush and high efficiency urinals were most often selected for lower (20+% or 30+%) water use reduction needs for WEc3: Water Use Reduction. Read the full report.