Net-Zero Energy Buildings: Semantic Antics

Pat Heffernan on October 26, 2010

Is obfuscation one of your goals? I didn’t think so. It does seem to be a goal in many architectural, energy efficiency and sustainability circles though. The terms zero energy building, net-zero carbon, net-zero energy cost, zero net energy, net-zero energy site, net-zero electricity, near net-zero, and net-zero ready…are all tossed about to describe a certain category of buildings that I have made the personal decision to refer to as “net-zero energy buildings” (or NZEBs).

Now as a self-professed word nerd, I recognize you may think this concern about terminology is my problem. Yet Wikipedia’s neutral point of view requires no less than six distinct definitions for ZEBs, including interesting differences between use of the term in the United States, Canada, and the rest of the world. (Note that in addition to ZEBs, Wikipedia adds additional definitions with separate entries for green buildings and sustainable architecture.)

Why does it matter?

Buildings consume over 40 percent of all energy and over 70 percent of all electricity used in the United States, and are responsible for about 40 percent of US carbon dioxide emissions. If there’s any hope of mitigating the effects of climate change, we need to get this right. Instead it sometimes feels as if, (excuse me), all our energy is being used to debate fine distinctions that do not matter in the larger scheme of things. (Shuffling deck chairs on the Titanic comes to mind.)

Major greenhouse gas trends

Image via Wikipedia

Major Greenhouse Gas Trends


Net-Zero as a Journey

I have written before about my aversion to thinking of net zero energy as a single end point.

I tend to think of net zero energy as a mindset rather than a single end point. True, there are those who favor purity, specific definitions and exact measurements whenever the term net-zero energy is used, but for a layperson like myself interested in change, there’s value in thinking in terms of a never-ending journey rather than a goal achieved.

Celebrate NZEBs

So, buildings use a tremendous amount of energy to operate and are a leading source of greenhouse gas emissions. We climate hawks need to work together. The goal of net-zero building design is to minimize energy use first through energy efficiency, and then meet any remaining energy needs with on-site renewable energy systems. Over the course of a year, these buildings will produce as much energy as they consume. That, to me, is a clear definition of a net-zero energy building. (In contrast, the term zero-energy building falsely implies to me that no energy was used to produce the building.)

If as Orwell wrote, we should use English to reveal rather than conceal, here’s to consistently using one term, net-zero energy building, and applauding every step on the journey to increasing their number. If you are interested in the fine distinctions, be sure to ask for the specifics of the definition being used for a particular structure — but please, only after celebrating the positive step forward.


Post written Pat Heffernan on October 26, 2010 in Buildings & Environment,Change communications,Energy efficiency,Framing

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