Everything You Need to Know About California's Net Zero Buildings

California is aiming for all new residential buildings to be Zero Net Energy (ZNE) by the year 2020, and all new commercial buildings ZNE in 2030. A ZNE building produces as much renewable energy as it consumes each year. So with such an ambitious goal ahead, how are we faring? Good thing you have Bisnow to tell you everything you need to know about California’s Net Zero Energy Buildings:

Pictured: The Cottle Zero Energy Home

Ann Edminster (pictured), expert environmental and ZNE design consultant, and author of Energy Free, points out the target is more of an aspirational goal than a mandate, but nonetheless, she believes it’s an achievable goal. She tells Bisnow a revised energy code is rolled out every three years (the upcoming 2016 code will go into effect January 2017), and while there will naturally be kinks to work out, she feels California is right on track.

Right now we have about 1,100 ZNE-type homes. Most are “ZNE-ready” or “Near ZNE,” but there are 16 actually ZNE. Since 2006, ZNEs in California have gone from representing 0.2% of the market to more than 1% in the first two quarters of 2014. Over 50 builders have constructed ZNE-type homes in 130 California cities, and of the 213 ZNE buildings known in the US, 40% of them are in California. So it’s safe to say California is making good headway.

The key to ZNE growth is educating builders and designers on the techniques for this type of construction. Making educational resources available to the community is a very important factor as ZNE buildings become the norm, which is why there are websites like Savings By Design that offer tools and incentives for owners who meet certain energy-efficiency requirements. (Pictured: The Cottle Zero Energy Home kitchen.)

So, what are some of the necessary technologies as we move toward a ZNE standard? For one, low-load mechanical systems will be a focus, Edminster says. "Mechanical systems used in conventional houses pump out too much heat and air for more efficient building envelopes, which require less energy to heat or cool." We can also expect to see improvements in photovoltaics (or rooftop solar panels), especially for taller buildings that have less surface area on the roof, compared to the overall size of the building. "As photovoltaics become more efficient, taller buildings in dense areas will be able to achieve zero net energy," Edminster says.

And what do homeowners think of net zero homes? Bill and Michelle Wong are very happy with their 4BR/3.5BA, two-story home in San Jose. The 3,200 SF Cottle Zero Energy Home, as it’s called, was built in 2012 by Allen Gilliland, founder/owner of One Sky Homes, and it was awarded the first net zero energy home in California by the California energy commission. How efficient is this home? After a cold snap in December 2013, their heating bill was $15…triple what they normally pay. The $1.76M home has 28 solar photovoltaic panels that provide 10,000 kWh of renewable electricity per year. It's also well-insulated and features triple pane windows and patio doors. In fact, it's so efficient you could heat the home with a hair dryer. (No joke, there’s actually a video.) (Pictured: The Cottle Zero Energy Home)

ZNE advocators are hoping that seeing the cool benefits of a ZNE home, like significantly lower utility bills, will make savvy homeowners want to get in on the trend early. This brings up another obstacle. "It’s difficult to determine ZNE home values because most real estate professionals don't know how to value a house that is both a home and its own personal utility," says Edminster. However, the ZNE community is working on a solution. However you look at it, ZNE will be the standard before we know it, so whether savvy buyers choose it today, or everyone else gets it later, ZNE homes are a certainty.

“It was a similar experience when we were discussing green affordable housing,” Edminster says. “Everyone was wondering if we could afford to make affordable housing green. Then green became a mandate and the discussion was over. Once a requirement is in place, all the arguments go away.” (Pictured: The Cottle Zero Energy Home)

Here are a couple more examples of ZNE buildings for your inner geek:

The Challengers Tennis Club: a 3,500 SF two-story building that uses 60% less energy than a comparable building thanks to a PV array on the roof that provides all the electricity the facility needs each year.

The Audubon Center at Debs Park: a 5,020 SF building, 10 minutes from Downtown LA, that provides educational programs for 50,000 children living nearby. This building is operated entirely off grid, using only 25,000 kWh of energy annually.