The number of net zero energy buildings in the U.S. has increased significantly over the last decade, and that has changed the perception of these facilities from being an unreachable ideal to a more attainable one.
The New Buildings Institute’s 2016 List of Zero Net Energy Buildings includes 332 facilities that have either verified net zero energy operation or committed to achieving zero energy, a massive increase from the 191 that made its 2015 list. As the industry continues to shift toward sustainable solutions, what kinds of paths are available for you to achieve certification as a zero energy building?
A Zero Energy Tipping Point
The Department of Energy defines zero energy buildings as those where, “on a source energy basis, the actual delivered energy is less than or equal to the on-site renewable exported energy.” This is usually calculated in 12-month increments, as consumption fluctuates throughout the year with changes in weather. As long as the facility gives as much energy back to the grid as it consumes, it is a zero energy building.
Green building practices have been around for decades, but zero energy buildings have slowly emerged across the country. However, as sustainability and cost-effectiveness continue to overlap, it seems as though zero energy buildings will multiply over the course of the next decade or two.
“I think we are at a tipping point. Right now we have about 65 projects that are certified as having achieved zero energy performance. We have about 400 that are registered as pursuing it through one of our certifications,” says Brad Liljequist, Zero Energy Director at the International Living Future Institute (ILFI). These projects widely vary in use and are categorized as residential, commercial and office, and institutional buildings. Most are new construction projects.
California leads the U.S. in zero energy buildings due to its favorable climate and incentive programs, and Portland, OR, and the north Atlantic coast are also leaders in net zero, according to the New Buildings Institute. There are either verified or emerging zero energy buildings in 39 states.
One indication that Liljequist cites as a harbinger for the future proliferation of zero energy facilities is that engineers and architects are not the only people discussing the concept of them. Even those without the expertise in facilities are more frequently coming in with a strong idea of the cost savings and additional benefits that can come with zero energy facilities.
“In the last year, I’m hearing average, mainstream people using the term ‘zero energy,’ which is telling me that we are going to see a very rapid acceleration in zero energy buildings,” says Liljequist. “Within five years, I think we’re going to be talking in terms of tens of thousands of zero energy buildings.”
Certifying Zero Energy Buildings
While there are a number of more general green and energy efficiency building certifications out there, the offerings for prospective net zero energy buildings are less common. Currently, there is one main certification for zero energy; the ILFI has had a program since 2011, and it was revamped in 2017 to create the Zero Energy Certification in partnership with the New Buildings Institute.
The goal of this certification is to provide recognition for facilities that achieve net zero energy usage for 12 consecutive months and to collect information that can be used to inform building owners of zero energy prospects. Over time, this will provide the foundation to perform metadata analysis that will aid their efforts to foster the continued adoption of zero energy buildings.
“We work quite a bit with projects that are in the process of achieving zero energy,” says Liljequist. “We do a lot of coaching, a lot of education through publications and classes, and actual consulting.”
In the update to its certification program, the ILFI looked to simplify the process for certification by reducing costs and documentation, focusing solely on energy performance in facilities and only requiring a third-party review of energy performance to receive certification.
For consideration, buildings need to be “fully occupied.” This doesn’t necessarily mean that the building needs to be filled 100% to capacity, but it needs to reach a capacity that represents full functionality for the organization and allow for possible occupant turnover.
The only real criteria for this certification is that the building must generate more energy than it uses over the course of a year. For many buildings that have sought out certification, it can take 6-12 months to get to zero energy performance if it is already close. Those that miss the mark can then reconsider things and find out what is wrong, explains Liljequist.