When designers Holly Zickler and her husband, David Rifkind, built their home in South Miami in 2011, the couple envisioned it as “a laboratory for socially and ecologically sustainable construction and planning in South Florida,” Rifkind says. With a much smaller resource-consumption footprint than almost any other building in the region, the 2,725-square-foot, single-story contemporary home is built mostly of recycled materials, and features a 5-kilowatt photovoltaic system that meets about 75 percent of the structure’s energy demands. But the idea of a net-zero-energy home—one that produces as much energy via renewable sources as it consumes from the grid—was not on their radar.
“This was our first attempt at sustainable design, and net zero wasn’t yet a part of our thinking,” says Rifkind, a professor of architecture at Florida International University. “We’re thinking of expanding our photovoltaic array to generate more power than we consume, however, since we now see net zero as an important goal.”
While zero net energy (ZNE) homes aren’t yet saturating the marketplace, they are on the way to becoming more common, thanks to progressive industry leaders and policymakers who have seized opportunities to reduce carbon emissions while reaping substantial economic rewards.
“State and local governments can’t look to Washington for help,” says Architecture 2030 executive director Edward Mazria, FAIA. “They need jobs, economic activity, and tax revenue now. ZNE legislation provides all three, with large returns on a modest investment.”
The new Colorado Energy Saving Mortgage Program, for instance, makes home buyers who are purchasing new or renovated ZNE homes eligible for an $8,000 reduction on financing the total cost of their mortgage. In New York, the Zero Net Energy Tax Credit Bill introduced to the State Assembly would offer considerable income tax incentives to home buyers who purchase a new or renovated net-zero home. And in New Mexico, the Sustainability Building Tax Credit, which provides personal and corporate income tax credits for both new and renovated high-performance commercial and residential buildings, was recently extended to 2016.
The architecture and design community at large also must embrace the shift towards ZNE, according to Passive House architect David Peabody, of Alexandria, Va.–based Peabody Architects. “What got me serious about high-performance design was when I realized that architects cannot sit on the fence on this issue when buildings are responsible for more than 45 percent of this nation’s carbon footprint, and residential architecture is responsible for more than 20 percent [of that],” he says. “We in the building profession are, then, either part of the solution or part of the problem, as the saying goes,” Peabody adds. “And if you see climate change as an intergenerational moral and ethical issue, indeed as an existential issue, then you have no choice but to address energy in a substantive way: true energy performance standards and true net zero—not gaming various green-building point systems.”
Rifkind adds, “A number of other factors—embodied energy, transportation, and water use, to name a few—are also crucial.” And Peabody agrees. “A commitment to build net-zero houses from now on will not reverse climate change,” he says. “It must be part of a whole panoply of changes that both reduce energy demand and replace fossil fuels. But getting to net zero is certainly a cornerstone of that effort.”
And that’s why Zickler and Rifkind’s home features a steel frame and prefabricated exterior panels, which consume just one-seventh of the energy needed to fabricate and erect a conventional concrete-block home in the area. The panels and steel frame are also known for their durability and resistance to the termite infestation common to the area. The lower embodied energy of the steel comes in part from its high recycled content and accounts for approximately three-quarters of the structural steel and almost all of the light-gauge framing.
The home also uses only electricity, thereby avoiding emissions associated with gas and oil, and it includes both rainwater filtration as well as graywater systems.
“We feel very strongly that every building and landscape provides an opportunity to stem the effects of climate change,” Zickler says. “Living 10 feet above sea level, along a hurricane-prone coast, has really sharpened our focus.”
Learn more about the house at somigreenhouse.blogspot.com.