Net Zero Certified: Two Buildings That Make More Energy Than They Use
We green building enthusiasts get excited about the vision of the net zero energy building — a structure that is energy-self-sufficient, using design and technology to harvest what it needs without any assistance from fossil fuels or the electrical grid.
I’ve heard of projects that claim to be net zero energy, but without having access to their data and design details, how can you judge such claims?
A few months ago, I reported on the new Centre for Interactive Research on Sustainability (CIRS) at the University of British Columbia (UBC) in Vancouver. At the time, UBC was billing the LEED Platinum-certified CIRS as “North America’s greenest building” and as net zero for both energy and water. The building is designed by Perkins+Will and incorporates solar energy, geothermal, rainwater collection, and other systems — it really is an amazing building. (Photo: CIRS building. Credit: Don Erhardt. Courtesy of the University of British Columbia.)
However, one important element of the design is that the CIRS gets much of its energy by harvesting waste heat from a nearby building. I wouldn’t call that cheating — it’s absolutely the right thing to do. But it does mean that the building is not exactly a stand-alone net zero structure. (See my article, “University of British Columbia Claims Credit for ‘North America’s Greenest Building‘” Dec. 5, 2011.)
Net zero energy is an exciting concept, but how do you evaluate any particular project’s claim to such a design?
That’s the problem that led to the development of a third-party standard, Net Zero Energy Building Certification (NZEBC), released in late 2011 by the International Living Future Institute. The new program was followed more recently (April 3, 2012) by the announcement that the program has awarded its first two certifications.
The Institute describes the new certification as “linked” to the organization’s larger Living Building Challenge certification. To qualify as a Living Building, a project has to meet 20 “Imperatives” in the categories of site, water, energy, health, materials, equity and beauty. The Institute calls its standard “the most advanced measure of sustainability in the built environment possible today” and “a unified tool for transformative design” providing “a framework for design, construction and the symbiotic relationship between people and all aspects of the built environment.”
The new Net Zero standard establishes four imperatives for projects to get certified:
- Site Imperative: Limits to Growth — The building should not contribute to “sprawled development” that “undermines the positive impact of achieving net zero energy building operations.” This requires that buildings go up only on greyfields or brownfields, i.e., “previously developed sites that are not classified as sensitive ecological habitats.”
- Energy Imperative: Net Zero Energy — The primary imperative for the standard, it prohibits combustion and requires that 100 percent of energy needs “must be supplied by on-site renewable energy on a net annual basis.”
- Equity Imperative: Rights to Nature — The building can’t prevent another building from achieving net zero energy by shading, and it “may not block access to nor diminish the quality of fresh air, sunlight and natural waterways to any member of society or adjacent developments.”
- Beauty Imperatives: Beauty + Spirit, Inspiration + Education — The building should educate the public about building solutions and “must contain design features intended solely for human delight and the celebration of culture, spirit and place appropriate to its function.”
Clean-tech research firm Pike Research recently projected that net zero energy buildings will represent a $1.3 trillion market by 2035. Pike Research references stiff new requirements scheduled to come into effect in the European Union (EU). The EU’s building codes will require nearly net zero energy performance in all public buildings by 2019, and then in all new construction by 2021. Pike Research says that “similar regulations have come into effect or are being discussed in the United States and Japan.” Research Analyst Eric Bloom calls net zero energy “the ‘holy grail’ in green building design.”
These emerging requirements make third-party certification crucial, according to Jason R. McLennan, CEO of the International Living Future Institute. The Institute’s announcement quotes McLennan: “Until now, it’s been impossible to know if projects claiming to be net zero are performing as expected.” He says he hopes that “those who pursue the net zero energy path seek to further transform the industry — and the world — by pursuing Living Building Challenge certification as the next logical step in project evolution.”
The first two projects certified under the program are an 80-year-old building converted to a community center at a mixed-use development in Salem, Ore., and a bank building renovated to an office building in San Jose, Calif.
Pringle Creek’s Painters Hall
Pringle Creek Community is a sustainable development in Salem, Ore., based on the integration of “green building, energy efficiency and respect to our natural environment.” The community is being developed on former state property three miles from downtown Salem. The 32-acre property includes 146 homesites, eight commercial lots and ample open and green space.
The project certified under the new Net Zero Energy program is Painters Hall (also a LEED Platinum project), a renovation that transformed a 1930s industrial building into a 3,400-square-foot community center. The project combines photovoltaic (PV) solar power, high energy efficiency, a real-time energy monitoring system, passive cooling, natural ventilation and daylighting.
Although the project uses solar power, James Santana, vice president of Sustainable Development Inc., the developer of Pringle Creek, says it got to net zero energy mostly through energy conservation, rather than on-site generation. He tells me:
“We used very simple, low-tech, low-energy systems to help us get there, and only after we had looked at every opportunity to reduce consumption did we go to on-site generation. The building models the kind of simple elegance and efficiency that can be achieved in a regeneration project, proving that oftentimes a simple approach is better.”
With all of the energy-conservation features of the building, its final electrical consumption came to only 600 kilowatt hours (kWh) per month, requiring only an 8-kW PV system to make up the difference. However, that would still leave the full solar potential of the building’s roof underutilized. For that reason, the team decided to install a 20.2kW total-rooftop solar system and use the excess energy to pump water through the community’s shared geothermal loop. This provides a source of heating and cooling energy for 77 homes and eight commercial lots in Pringle Creek.
The Painters Hall renovation involved gutting the existing building. However, an important element of the project was minimizing waste and reusing materials. Santana, writing about the project for Solar Today (“Pringle Creek’s Path to Net Zero,” Sept./Oct. 2010), says that “ultimately, 90 percent of the demolition waste was diverted from landfills.” Santana describes some of the measures taken by the project team:
“After the gutting, the building’s shell was all that remained: trusses, roof sheathing, concrete walls and foundation. Drawing from a stockpile of metal, wood and concrete saved from other buildings deconstructed on site, local green builder Phil Klaus, of Spectra Construction, began to give new uses to old materials. The front porch decking was built of salvaged old growth timbers. The trellis, door pulls, bike racks and conference table came from old steam pipe and stanchions. The cafe bar, table tops and furniture were made from hazard trees milled on site. Acoustical ceiling slats and trellis shading were made from tongue and groove fir pulled from the building next door.”
Santana tells me that the energy-related elements of the Painters Hall project were only one aspect that led to the Net Zero Energy certification:
“The NZEB certification and the Living Building Challenge require that a building provide its own energy but also be inspiring and beautiful, delightful, a joy to be in. The building must restore the health of our social and ecological communities. Painters Hall is a hub for community gatherings and activities — civic groups, cafe, offices, meeting space, event space, informal parties. It is a place where people with common interests can gather to share their interests. For that reason I would say the most important element of the certification is not solar panels or energy efficient systems. It’s community, which is probably the most valuable form of energy the building will give back over its lifetime.”
IDeAs’ Z2 Design Facility
In the second certified Net Zero Energy project, an engineering group transformed a 1960s-era bank building into its new headquarters facility. Integrated Design Associates (IDeAs) of San Jose, Calif., and Denver, Colo., specializes in electrical engineering, daylighting, and lighting design. But beyond those specialties, they advocate and practice “integrated design,” looking “beyond the scope of the electrical systems to larger issues such as indoor environmental quality, aesthetics, maintenance, overall energy efficiency and financial performance” of the buildings they design to seek an “in-depth understanding of the interactions between building systems.”
IDeAs has applied that kind of integrated design process in the development of its 10,000-square-foot Z2 Design Facility. The building uses no fossil fuels for electricity, heating or cooling and employs rooftop PV solar panels to generate more electricity than it consumes.
David Kaneda, managing principal of Integral Group, a green engineering firm and IDeAs’ parent company, calls the Z2 Design Facility building “a ‘proof-of-concept’ design that shows that a common type of existing building can be remodeled into a high performance, net zero energy, zero carbon emission building.” He tells me:
“It is believed to be the first commercial office building in the U.S. to meet this standard. The ability to take a standard building and redesign it into a high performance building has profound implications for the environment and the construction industry. We believe that this building will help move California, the United States, and eventually the world to a future where not only do new buildings not contribute to global warming but existing buildings gradually reduce their negative impact on carbon emissions and global warming.”
Kaneda thinks certain features of the building were particularly relevant to obtaining the Net Zero certification:
- A well-designed building skin that “takes advantage of the thermal mass of the building and effectively controls solar gain”
- A system for lighting and daylight harvesting that uses less than seven percent of the energy of a conventional office of the same size
- “The first example of a comprehensive plug load reduction strategy to minimize the plug loads in the building.”
- An all-electric building designed “with a photovoltaic system sized to generate 100 percent of the annual energy use of the building”
The Z2 facility is also serving as a kind of live laboratory for studying energy efficiency, says Kaneda. The building includes a circuit monitoring system that allows occupants to “study where and how energy is used throughout the building.” This has resulted in “important insights into where to look for energy reduction within an office building and how to motivate occupants to change behavior to reduce energy use.”
Kaneda believes the International Living Future Institute has settled an important problem by establishing the new Net Zero Energy Building Certification. Previously, he tells me, “there were many projects claiming to be ‘net zero energy’ and different definitions and many questionable claims of net zero energy.” The new standard, though, provides independent verification and will “add rigor to the claims of designers and owners of net zero energy buildings.”