The EPA just released a new national residential water-use study that compares indoor and outdoor water consumption data from three categories: existing homes originally studied in 1999, “standard” homes built after 2001, and new “high-efficiency” homes built to equal or exceed WaterSense performance criteria. The first new study in a long time, it reveals significant improvements under way while identifying critical areas that need to be addressed as new priorities. Researchers from Boulder, Colo., water engineering firm Aquacraft worked with water utilities in nine cities to collect data from each group in each city, including real-time monitored water consumption from the new homes. Visit www.aquacraft.com to view the full report. —Rick Schwolsky
INDOOR WATER USE IN HIGH-EFFICIENCY HOMES
Showers emerged as the single largest source of indoor water use. ¬Weve got to get people to shorten their showers,® says study author William DeOreo, president of Aquacraft. ¬Low-flow showerheads [alone] arent doing it.® And while leaks account for 18% of indoor water use, few builders install leak detectors as part of their efficiency package. ¬We need to identify and then interfere with leaks,® DeOreo says.
BENCHMARKS FOR EFFICIENCY
Existing homes in the study consume an average of 190 gallons per household per day (gphd). High-efficiency homes can reduce that to less than 110 gphd by following WaterSense standards and limiting leakage to 20 gallons per day or less.
COMPARISON OF INDOOR CONSUMPTION
This chart shows improvements in indoor water efficiency comparing existing homes studied in 1999, ¬standard® homes built since 2001, and ¬high-efficiency® homes built to EPAs WaterSense standards.
WATER USE AND OCCUPANCY
As this chart demonstrates, per-capita indoor water efficiency improves as the number of occupants in a high-efficiency home increases.