Innovation in the housing industry usually takes the long road on its way into the mainstream, and its arrival is not typically noted until we see its evidence and acceptance among production builders in major markets. So when Pulte Homes committed to building water-efficient homes in Las Vegas as part of the EPA-sponsored Water Smart Home study, it was a sign that “water efficiency” has arrived.
Las Vegas is one of nine municipalities included in the 2010 national study; working with the Southern Nevada Water Authority (SNWA), Pulte agreed to outfit 20 new homes in that market with water-saving features and products ranging from pressure-limiting water-main valves to “smart” landscape irrigation systems.
Information gleaned from monitoring these homes will help set a benchmark of how newer, high-efficiency homes with water-saving features contrast to standard homes built over the past decade, and to water-use data collected by the EPA since 1991. (For more on this just-released national study, see GreenWatch, page 64.)
According to SNWA conservation manager Doug Bennett, the Las Vegas study is notable because it is using a national production home builder to demonstrate how affordable, high-efficiency water-saving products and features can be incorporated into any home.
Bennett cited the EPA study results that show how residential water use nationwide has increased over time despite public and private conservation efforts, mostly due to larger home sizes and “upscale” owner options such as dishwashers and landscape irrigation—amenities once limited to custom homes but now commonly installed. Although the study shows that newer homes use less water indoors, outdoor water use has increased to the point that total household water use in the newest homes was higher in seven of the nine jurisdictions in the Water Smart program. Only Phoenix and Las Vegas show new homes using less water overall.
Water efficiency is nothing new for Bennett and the SNWA, which has certified 8,400 water-efficient homes in its own Water Smart Home Program. And many of the measures you’ll see in the EPA’s WaterSense Home program have their roots in SNWA’s own criteria. Bennett is keen on encouraging practices based on products that he says “must be affordable, readily available, and off-the-shelf technology” in order to keep water-efficient housing affordable to buyers, but also so that builders “can use standard construction practices.”
Pulte’s Las Vegas homes are not all outfitted the same way, or with the same equipment, which will allows researchers to collect a wider range of data. While buyers are not obligated to monitor or maintain any of the equipment installed in their homes, some units have “dashboard” monitoring panels that will enable researchers and occupants to view real-time and accumulated performance data. Most of the water-efficient products in the Pulte homes are either Energy Star or WaterSense certified, including 1.28-gpf toilets, 1.5-gpm bath faucets, and 2.0-gpm showerheads. Bennett says homes that incorporate these specs can cut annual water use in half—from almost 200,000 gallons on average to around 90,000 gallons a year. To achieve the maximum efficiency, he adds, low-water landscaping features are especially important.
Some of the other products go beyond the standard plumbing equipment found in most homes. For example, an adjustable pressure reduction valve (PRV) installed in each home helps maintain a maximum water-supply rate of 60 psi, which provides optimum efficiency at the home’s various fixtures, and a secondary “sub-meter” installed in the study homes will help researchers monitor indoor water use separately. Pulte also installed leak-detection devices—some equipped with auto-shutoff controls—to help reduce the significant waste attributed to water leaks. In addition, the homes include water-saving front-loading horizontal-axis clothes washers.
Details that aren’t in themselves water-efficient still contribute to conservation, such as high-efficiency tankless water heaters installed close to fixture outlets to help reduce “waiting-time” waste, and plumbing the units with small-diameter PEX tubing.
By all accounts, water use outside the home outweighs the consumption inside, especially in dry climates, so Pulte also followed SNWA’s Water Smart Home criteria there. This includes requirements for limiting the turf to only the side and back yards and 100 square feet or less, and installing xeriscape landscaping that can greatly reduce outdoor water use. Pulte also installed a variety of water sensor– or weather-based “smart” irrigation systems.
Bennett estimates the total cost to builders for the products used in these homes at $300 and $500 per house, including low-water plantings. An added benefit to building with such features, he adds, is that they bestow “green home” status—even on production-built houses. “These homes are Water Smart,” says Bennett, “but they also have the potential to meet LEED certification standards.”
Mike Morris is a freelance writer based in Ossining, N.Y.