Anatomy of a Net Zero Home

Anatomy of a Net Zero Home

KB’s latest net zero home

The next big thing in energy savings and eco-friendly homes? Water savings.

Drought in the west, imminent water shortages, mandates in California and other states make water saving systems for new homes a must. And if it helps save on water bills elsewhere, all the better, right?

KB Home has upped the water-savings ante with its “Double” ZeroHouse 2.0 project in Lancaster, Calif., going so far as to use a graywater recycling system that, along with green building, solar technologies and a Schneider Wiser energy management system, can save an estimated $4,452 in water and energy bills annually, according to the homebuilder.

The Double ZeroHouse 2.0 at Dawn Creek in Lancaster can conserve 150,000 gallons of water each year when compared to a typical resale home and landscaping, a reduction of approximately 70 percent. The Double ZeroHouse is a WaterSense-labeled new home, designating water efficiency. In addition, the ZeroHouse is designed to produce as much energy as it consumes, potentially yielding an electric bill of $0.

ZeroHouse features and technologies can be added as part of KB Home’s Built to Order experience starting at $50,000, and more for upgrade packages. Base prices of homes at Dawn Creek in Lancaster range from $287,990 to $358,990.

Here’s a look at some of the water- and energy-saving innovations that make these savings possible:


Centralized and Structured Plumbing

KB Home floorplan“We locate the highest hot water demands—the kitchen, bathrooms and laundry areas—as close as possible to the hot water heater,” says Jacob Atalla, senior director of Sustainability Initiatives at KB Home in an interview for WaterSense. “By designing our homes with kitchens and baths concentrated in one area of the house, we vastly reduce the length and complexity of the required plumbing runs.” Reducing the required lengths of the plumbing reduces the building costs as well.

The centralized floor plan is coupled with structured plumbing principles that use miniature manifolds and pipes with smaller radiuses. “These effectively create a network of smaller ‘branches and twigs’ that distribute hot water from the main ‘trunk’ while maintaining more heat,” Atalla explains. This smart design can preclude the need for an on-demand hot water recirculation pump and help increase hot water efficiency dramatically.


Graywater Recycling and Heat Recovery

Pipe diagramThe home’s water recycling system treats graywater from bathroom showers, tubs, sinks and washing machines to near-potable quality, and reuses it on the landscape. KB Home’s ZeroHouse 2.0 at Dawn Creek is the builder’s first to showcase this cutting-edge technology that, according to manufacturer’s estimates, can help a family of four recycle up to 40,000 gallons of water annually.

Graywater flows through a Nexus eWater treater for filtering and a drain water heat recovery system called Power-Pipe from RenewAbility. The Power-Pipe uses multiple coils wrapped in parallel around a central drain pipe to extract heat from the used water before it heads to the graywater collection tank. A Power-Pipe also preheats new fresh water before it heads to the tankless water heater for domestic use, further reducing water heating costs. Two graywater tanks are used: one that collects the graywater and one that stores the recycled treated water ready for irrigation. 


Not-so-Cool Fact

The average household wastes 3,650 gallons+ per year waiting for hot water, according to WaterSense.


Water Recycling Dishwasher

KitchenAid Water Recycling DishwasherKitchenAid’s 24-inch 5-Cycle/6-Option Architect Series II Dishwasher uses 33 percent less water than other highly efficient dishwashers by saving water from the last rinse cycle for use in the first pre-rinse cycle of the next load. In addition, a ProWash feature determines the appropriate cycle for washing dishes and makes real-time adjustments for the best cleaning performance, and a ProScrub option uses 40 targeted spray jets at the back of the dishwasher to help eliminate soaking or pre-scrubbing. Isn’t it cool how easy it is to save and reuse water for features like toilet flushing and pre-rinse? Our hunch is that we will see a LOT more of these water-saving and reuse systems in the future.


Solar SystemsKB Home solar

To get to a Net Zero home that produces all of its own energy, KB Home starts by employing efficient building techniques to bring a HERS (Home Energy Rating System) Index score of between 40 and 50, then produces the energy needed to operate the home with solar panels from SunPower. KB also offers SunPower solar PV systems in packages of 1.8-kw, 2.5-kw and 3.25-kw systems, depending on the home size, and upgrades to larger systems available as options.‎


Super-efficient Air VentilationKB Home solar

An advanced ventilation system introduces fresh outdoor air into the home via a Carrier energy recovery ventilator (ERV), that uses the heat from stale outgoing air to warm the incoming air if needed, while a whole-home air purification system combines patented electronic technology with a highly efficient filter to significantly improve indoor air purity and increase airflow.


Smart House and Energy Monitoring

The ZeroHouse is connected to real-time water and energy monitoring systems that can track the water and energy used by the house conveniently from smart phones and tablets. Home automation technology included in the home puts the power to control its lighting, thermostat and security functions at its owners’ fingertips with Schneider Wiser smart home technologies including Kwikset Connect locks.

Video: see the KB Home Smart Home and energy monitoring features in action!


Smart Appliances

The home’s ‘smart’ refrigerator further reduces the home’s demand for energy by shifting energy-intensive functions to off-peak times. This type of load-shifting is possible through utility-based smart grid programs like Demand Response (DR) and variable Time-of-Use (TOU) pricing.

Smart and connected appliances by Whirlpool can be monitored and operated by smarthpone apps to control, monitor, check the diagnostics of appliances, run or delay cycles. The Lancaster home also has a high-performance attic from Owens Corning, as well as electric vehicle (EV) charger from Schneider.

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