Real Estate News

New El Dorado Hills house recycles wash water and makes its own energy

A demonstration house unveiled in El Dorado Hills last week by national builder KB Home recycles drain water for toilets and landscaping and can power itself entirely with solar panels. Its innovative systems are compact and unobtrusive, and will likely come down in price, making them viable upgrades for new home buyers in coming years, company officials said.

“These are futuristic things, but they’re systems you can do today,” said Dan Bridleman, the company’s senior vice president for technology and sustainability. The features are still relatively expensive, but Bridleman said the cost will fall sufficiently over time so that homebuyers will see a built-in water recycling unit or a house that doesn’t need to draw power from the grid as a “good value proposition.”

KB’s 2,600-square-foot “Double ZeroHouse 3.0” is located in its Fiora subdivision in Blackstone, a 990-acre master planned community along Latrobe Road. Blackstone, like other communities in El Dorado Hills, uses recycled water produced by the area’s two wastewater treatment plants to water lawns.

Water recycling has been gaining momentum in California’s historic drought. Cities including Sacramento are planning to use more of it in coming years for landscape irrigation and to cool power stations. Most recycled water is produced by large municipal wastewater plants.

The Double ZeroHouse takes water recycling to the next level by providing on-site treatment in a system developed by an Australian-American venture called Nexus eWater. The system isn’t approved for household use yet, but company officials say they expect the state to certify it within the next year.

The system gathers gray water from showers, sinks and washing machines in an underground 80-gallon reservoir that looks like a black plastic barrel. Above ground, in a locker-size treatment unit, contaminants such as hair and lint are bubbled out with soap and air, said Tom Wood, Nexus eWater’s chief technology officer.

Wood, who is Australian, spent part of last week installing the system at the KB house in El Dorado Hills.

The water is filtered multiple times, then sterilized with ultraviolet light, Wood said. It’s stored in a clean-water reservoir until it’s needed to fill toilets or irrigate the lawn. A large portion of household water is used a second time before it sinks in the soil or gets flushed away.

“It gives a second life to every 2 out of 3 gallons of water in your home,” said Nexus eWater chairman Ralph Petroff, who was also at the construction site last week.

Petroff said his company has installed two similar systems, one at a house in Encino, in the San Fernando Valley, and another at a KB Home project in the Mojave Desert city of Lancaster called Double ZeroHouse 2.0. That house also recycles water and produces its own electricity.

The El Dorado Hills house is the first in the nation to reuse the residual warmth in its gray water to help heat fresh water, Petroff said. The heat from shower and laundry wastewater is collected and put to use in an oversized orange-and-silver water heater in the garage.

The water-recycling system costs about $5,000, company officials said, plus several thousand dollars to install it in a new home. Retrofitting an existing house would be far more expensive, they said.

Inside the house, a variety of high-tech appliances help save additional water and energy. A refrigerator knows when electricity rates go down at off-peak times and makes ice then. A Kitchen Aid dishwasher recycles the water from its final rinse and uses it to wash debris from dishes at the start of the next cycle.

Insulation in the attic is on the ceiling, not the floor, and the attic’s temperature is controlled so that heating and air conditioning ducts aren’t exposed to broiling temperatures in summer and freezing air in winter.

Lights, locks and temperature can be controlled by smartphone and tablet apps. Electricity and water usage can be monitored in real time on smart TVs.

The whole house is powered by solar panels on the roof that KB officials said were the most efficient available. They’re produced by SunPower Corp., a company based in San Jose with offices in Roseville. The panels feed an energy-storage unit that can power the house overnight, in the case of the grid going down, then be recharged from the rooftop panels once the sun comes up. The batteries are another first for KB, officials said.

“In the case of El Dorado Hills, we wanted to put the technology through its paces,” said Jacob Atalla, KB’s vice president for sustainability.

The electrical upgrades will add about $40,000 to the cost of a new home, but the house can produce as much energy as it uses, potentially reducing electric bills to zero, Atalla said. The estimated savings are about $4,500 a year for electricity and water compared to the costs of utilities for a similar-size home that’s 20 years old, he said.

“Dollars are what’s important to the customer,” Atalla said.

The KB Double ZeroHouse is at 613 Colby Court in El Dorado Hills. It’s open to the public daily from 10 a.m. to 6 p.m. For more information, including directions, go to