If I were a betting woman, I’d put my money on zero—it seems to be quite a winning number these days. Zero has plenty of negative associations (zero balance in the bank account) and several positive ones (zero hassle, zero upfront fees, and we all know that the cookie crumbs have zero calories). Now, it seems that zero has become the darling of the green building sector.
Net zero energy buildings—or buildings that produce as much energy as they use through the incorporation of efficiency, renewables, and occupant behavior—are all the rage.
A building’s energy performance can be measured with tools similar to a miles-per-gallon sticker for cars, such as the HERS Index Score issued by the Residential Energy Services Network (RESNET). With a HERS rating, a low score is indicative of higher energy efficiency and performance.
According to RESNET, a typical American new home that is built to code is rated at 100 on the HERS index, and a typical American resale home is rated at 130 (so, homes that are resold are generally 30% less efficient than today’s code compliant new homes). The Department of Energy asserts that a home can be considered to be net-zero energy if it has a HERS rating of 30 or below.
Net-zero energy is an excellent goal and certainly a huge step forward for the construction industry. With that said, I would be remiss if I didn’t add the caveat that if we’re only measuring energy, we’re not assessing the full sustainability of a structure.
Green building initiatives across the country are attempting to incorporate the concept of net zero energy with other sustainability considerations to achieve comfortable, healthy, and affordable buildings. For example, BASF’s BEYOND program offers a building-science based approach for creating homes with an interesting rule of thumb that net zero energy can be achieved 50% though building performance and efficiency, 30% through the incorporation of renewable energy, and 20% through sustainable occupant behavior.
The drive to zero is not about energy performance alone. The concept has penetrated other important areas like water and waste as well. One example of a successful net zero waste initiative in our industry is the ambitious program implemented by DuPont’s Building Innovations group.
In a recent interview, DuPont’s Building Innovations President, Tim McCann, told me that, “DuPont’s construction division wanted to figure out how to deal with waste. We set a goal to be landfill-free in a 3 year period, dealing with everything in our waste stream. We had people from production, maintenance, engineering, and operations looking at each waste stream, and we reengineered our products to eliminate waste. Now, we reuse, recycle, or use all of the waste for BTU value (only 2% is burned for BTU value). We sent 81 million pounds of waste to the landfill in 2008, and now we send zero waste to landfills.”
When I asked him why DuPont focused on zero waste as opposed to other sustainability initiatives, Tim responded that “waste minimization is a good sustainability goal. It’s easy to understand and measure. People, including our leadership, employees, and customers, can understand it and apply it to their daily lives.”
Indeed, zero is a winner. It’s an achievable goal and clearly the next stage in our journey to a sustainable future.
With that said, I’m interested in what lurks beyond the zero horizon. I’m excited to partake in the shift from zero to regenerative, where we’re not just breaking even, we’re actually producing clean energy, water, and air, and having a positive effect on habitats, natural systems, and living beings.
Green Builder Media’s newest demonstration project, the VISION House Tucson, is an attempt to go beyond net zero. Not only is it designed to use half the water of a typical American home, minimize waste, maximize resource efficiency, and enhance occupant comfort and livability, it is modeled to have a HERS rating of negative 17, meaning that it’s expected to produce more energy than it uses and sell power back to the utility.
We hope that the VISION House Tucson will serve as an example for the next generation of housing in our country. In the coming months, we look forward to sharing with you the challenges that we encounter and successes that we enjoy during the process. Follow our progress at www.greenbuildermag.com and give us your feedback.
What innovative, regenerative ideas are you using in your projects? Write to me at email@example.com or follow me on Twitter @SaraGBM.
For more information about green building and sustainable living, visit www.greenbuildermag.com, like us on Facebook, and follow us on Twitter at @greenbuildermag and @VISIONHouseGBM for regular updates and breaking news.