Project Credits

Project Double ZeroHouse 3.0
Location El Dorado Hills, Calif.
Builder KB Home, Los Angeles
Size 2,612 square feet
Date Opened October 2014
Top Water-Saving Technologies Low-flow fixtures, graywater-fed toilets, drip irrigation, wastewater heat extraction, ultra-efficient dishwasher

Although KB Home is known for its innovative approach to energy-efficient home building, the firm has also long been committed to residential water conservation—even though few consumers are concerned about saving water.

But Americans' careless attitude on the topic may be about to change, at least in California, where a massive drought prompted Gov. Jerry Brown to call for a mandatory 25% reduction in potable urban water use this spring. The legislation was due in part to the fact that Californians fell 11% short of his 2014 request to cut consumption by 20%.

"This is the drought of the century, with greater impact than anything our parents and grandparents experienced, and we have to act accordingly," says Felicia Marcus, chair of the State Water Resources Board.

KB Home officials have been paying attention, even if buyers haven't. In fact, just a few months before the governor's anouncement, the Los Angeles–based production builder completed its latest water-saving demonstration house, Double ZeroHouse 3.0, at its Fiora at Blackstone community in El Dorado Hills, Calif., east of Sacramento. Like KB Homes' previous Double ZeroHouse 2.0 models, the solar-powered 3.0 version is designed to achieve net-zero energy along with industry-low levels of water usage.

The house is a living laboratory of real-world water-saving innovations including a first-of-its-kind KitchenAid Architect Series II water-recycling dishwasher—which uses one-third less water than traditional models by saving the water from the last rinse cycle to pre-rinse the next cycle—Kohler and Moen WaterSense-labeled fixtures, and a touchless kitchen faucet. With these measures alone, the house will save about 30,000 gallons of water a year at no additional cost to buyers, says Dan Bridleman, KB's senior vice president of sustainability. "We can leverage our size and volume and do these things to save water while realistically having no cost increases passed on to the consumer," he says.

Cutting Back in California

For the first time in history, California residents are facing mandatory conservation measures designed to alleviate shortages from a four-year-long drought. The restrictions affect homes, businesses, and local water suppliers, and are punishable by fines of up to $500 a day.

For individuals, the emergency regulations prohibit:
--Using potable water to wash sidewalks and driveways;

--Allowing runoff when irrigating with potable water;

--Using hoses with no shutoff nozzles to wash cars;

--Using potable water in decorative water features that do not recirculate the water; and

--Irrigating outdoors during and within 48 hours following measurable rainfall

Other innovations boost water efficiency even further: Motion sensors in the upstairs bathrooms signal recirculation pumps to bring instant hot water to sink faucets when a resident enters the room. Toilets are supplied by filtered graywater, something that's only allowed in a few California cities. The drought-tolerant landscaping is watered by a graywater-fed drip irrigation system.

But perhaps the home's most innovative feature is its ability to reuse heat from warm water as it flows down the drain from showers, sinks, the clothes washer, and dishwasher. An integrated water and energy recycling system from Australian-based Nexus eWater extracts heat from warm graywater, which studies show accounts for 2 out of every 3 gallons of indoor water. The system supplies this "recycled energy" to heat the home's fresh water, helping the hot water heater to use up to 30% less energy.

KB estimates that the 2,612-square-foot house can conserve as much as 70% of the freshwater used in a typical resale home. Although many of the techniques are not yet widely available to buyers, all homes at Fiora meet the EPA's WaterSense for New Homes criteria, and the firm recently announced plans for a new luxury community in San Diego called Sea Cliff, which will include graywater recycling as a standard feature. It's all part of the company's plan to introduce water-conscious products to the wider market, which is only now starting to see the urgency of the situation.

"If something is so far out of range that people can't afford it then it's not going to work," Bridleman says. "So we have to make new ideas accessible to buyers while still testing and vetting cutting-edge innovations that will be a huge benefit to people in California and other areas where water is in short supply."