Net-zero isn’t a new way of doing things, but the building principle that prioritizes producing more energy than a structure consumes is finally coming into its own.
Net-zero eliminates the use of fossil fuels like natural gas in homes by swapping in electric options, powered by on-site energy solutions like solar panels and wind turbines. The once-fringe technique is winning support from internationally lauded architecture firms, small developers, and conscious consumers who are seeking a way to tread more lightly on the earth without compromising creature comforts or their design ideals.
Take Sawmill House, built by the Seattle-based architecture firm Olson Kundig in California’s high desert, where summers are scorching and winters are brutal.
Overhangs help shield the home from the sun, allowing it to remain at a more stable temperature during the warmer months, while heavy insulation helps the home retain heat in the winter. A similar technique is used in passive-house construction, which utilizes passive attributes like sun and shade alongside triple-glazed windows and insulation to maintain the home’s interior environment for an energy-efficient structure.
Sawmill House, designed for a chemical engineer and a ceramicist, “was designed to maximize daylight, solar energy, and natural ventilation,” Tom Kundig, an Olson Kundig principal, said.
The result is a net-zero, off-the-grid house that runs on solar energy and generates 96% less carbon dioxide than a comparable building. (Or 100% less, if you don’t count the propane used to run the grill, Kundig said.)
Olson Kundig has designed a spate of design-forward, net-zero homes across the United States and Canada that prioritizes using renewable-energy sources over fossil fuels. The projects not only renewable-energy sources to power the properties, they also often loop in recycled building materials like steel and reclaimed wood to further reduce a home’s environmental impact.
Sawmill House, for example, was constructed in part with reused and recycled materials, including 25 tons of steel salvaged from a decommissioned cement plant nearby. This not only removed the materials from the waste stream but also helped the homeowner save an estimated $40,000. Because Sawmill is off-grid and uses solar energy, the home has no annual utility costs beyond the roughly $500 its owners spend on propane each year.
While net-zero homes require an initial investment to buy and install the technology and systems that will maintain the house, they make up for it in energy savings over time. The systems have also become less expensive over the years, lowering the economic barrier for who can afford to build a net-zero home — though there’s still a ways to go in making it an attainable option for a larger swath of the population.
Mark Z. Jacobson, a Stanford University professor of civil and environmental engineering, completed his own net-zero home in 2017. The Stanford, California, property features energy-efficient appliances alongside other hallmarks of net-zero homes like good insulation and LED lighting .
Through on-site solar panels, the home has produced, on average, 120% of the electricity it needs to run over the past five years. The 20% of electricity sent back to the grid has generated more than $4,000 in payments to Jacobson from Silicon Valley Clean Energy.
“The solar and battery systems have been totally paid off,” Jacobson said. He estimates he’s saved $16,000 by eschewing a gas hookup and piping in favor of a system powered by electricity, and has saved $30,000 in utility costs over five years. Jacobson said he also received $40,000-plus in subsidies, citing a 30% federal tax credit for solar and a state credit for the batteries used to power the house.
The Stanford home has even gotten the glossy shelter-publication treatment, with a feature on Dwell showingcasing its ultramodern interiors. “You can’t tell this is any different from any other modern home,” Jacobson said.
The floors are hickory and marble, and he has all the appliances one would expect in a modern home. He also mentioned that in the five years he’s lived in the house, not a single LED light bulb has needed replacing.
The idea that energy efficiency in design can create an equally, if not more pleasing, interior is one that the Brooklyn Home Company founder Bill Caleo also embraces. The small New York development firm hews to the principles of passive house, a technique similar to net-zero that Caleo describes as “a European building technique of creating a super energy-efficient home, lowering your carbon footprint, and reducing your heating and cooling bills by about 50%.”
Caleo said he’s seen an uptick in interest in properties of his firm has developed during the pandemic, not only because of their energy efficiency but also because of the air quality that comes with this kind of development. The Brooklyn Home Company recently completed a 14-condominium building called Timber House in the borough’s Park Slope neighborhood with rooftop solar panels, triple-glazed windows, and energy-recovery air-filtration systems that promote energy efficiency and air quality.
“Coming out of COVID, people are more and more curious about passive house because of the filtered fresh air and staying healthy inside,” he said.
Jacobson also noted that net-zero homes don’t experience the air pollution that traditional homes do from burning gas.
As the technology to create buildings that use clean energy more efficiency becomes more available, adopting a more widespread embrace of the practice feels like a no-brainer.
For Jacobson, it’s pretty simple: “There’s nothing that natural gas can do that electricity can’t do better — and cleaner.”