There’s an old joke about how standards proliferate. A particular industry (let’s say, for argument’s sake, the one that deals with buildings) gets bogged down by 14 competing standards and definitions of the same thing. The solution is to concoct a universal definition that encompasses all scenarios, one standard to rule them all. The result: the industry now has 15 competing standards.

Is this an unfair generalization? Yes. Because the gag’s premise rests of the idea of competition. If varying standards of the same thing are designed to complement one another—counterintuitive as that might seem—rather than compete, then we must take solace that everyone’s aim is true and fixed on the same target.

One definition

In that spirit, this past January 3, the U.S. Department of Energy’s Building Technologies Office released a request for information to solicit feedback from various industry stakeholders on the working draft of a “National Definition of a Zero Emissions Building: Part 1 Operating Emissions.” (Note: the public comment period ends on February 3.) Such an effort is obviously in keeping with the Biden-Harris Administration’s climate goals, which include achieving a 100% clean energy sector by 2035 and making zero emissions for new construction commonplace. The intent, according to the draft, is to create a “standardized, consistent, measurable basis” for zero emissions, and a “clear market signal” that will incentivize the building industry to act accordingly.

“For decades, many parties across the American building sector have developed different interpretations of what a zero-emissions building is or should be, and we haven’t had an agreed upon definition at the national level,” says a senior DOE official. “This has resulted in a landscape of numerous definitions that all have slightly different specs for architects, engineers, and builders. Since the standards are not clearly set, there’s tremendous confusion. It leads to paralysis by analysis.”

For what it’s worth, a who’s who roster of design firms has already coalesced around the federal effort, with 69 firms expressing support and signing a statement—organized by Maine-based OPAL—that reads, in part, “A uniform definition, verifiable through federal agencies, will unlock more public and private investments in emissions-effective and resilient buildings across a diverse array of real estate.” As market signals go, the industry could do a lot worse than this. And in terms of market forces, the likes of the USGBC and International Living Future Institute (ILFI) need not worry about the federal government encroaching on their territory.

Many definitions

In the most literal sense, a zero-emissions building is one that is free of on-site greenhouse gas emissions from energy use, with non-negotiable prerequisites like energy efficiency and clean energy. That’s the big picture, nuance free and all. But buildings are complex and finnicky beasts, subject to fluctuating climate conditions, material deficiencies, and all manner of technical and maintenance concerns (aka human error). With that knowledge, organizations have held fast to the technical definition but tweaked the methods by which one can attain it.

For LEED’s Zero Carbon certification, for instance, to achieve a CO2e balance of zero (total carbon emitted minus total carbon avoided), on-site renewable energy generated and exported to the grid, off-site renewable energy procurement, and the purchase of carbon offsets, such as renewable energy certificates, are all fair game. Further, in a bit of creative arithmetic, on-site fossil fuel combustion is permitted, to a degree. Adversely, ILFI’s Zero Carbon certification prohibits any use of combustion, save for natural gas, which is permitted on existing projects, and off-site renewables are applicable except for purchased credits.

In both instances, each standard closely adheres to the New Building Institute’s Five Foundations of Zero Carbon Building Policies: energy efficiency, renewable energy, building grid integration, building electrification, and embodied carbon. Of course, depending on which standard one pursues, the variables used to reach true ‘0’ will differ. The foundations of mathematics may be the same in every corner of the universe, but as a logistical matter, getting to “zero carbon,” “zero energy,” and/or “zero emissions” is evidently subject to poetic license.

The Department of Energy’s attempt to set a national definition is not meant to introduce a disruptor or become the proverbial 15^th standard but, in the Administration’s words, empower green building programs to “embed the definition within their certifications.” This largely mirrors the ASHRAE model, in which specific language and benchmarks are laid out in detail and await adoption by third-party programs, municipalities, and others to integrate into building and energy codes. The working draft even cites specific sections within ASHRAE Standard 228 (the evaluation standard for zero energy and zero carbon buildings) as valid guidelines for qualified clean energy procurement in pursuit of zero emissions.

“In speaking with so many different building owners in the market, as well as green building certification groups, it became very clear there was a gap in the market in terms of what our clear direction for the building sector is,” says Heather Clark, director of building emissions at White House Climate Policy Office.

Starting with operations

The working definition is focused on three areas of operational emissions: high energy efficiency, eliminating on-site emissions, and implementing building-specific clean-energy production. There is no mention of building types or prescriptive pathways or life cycle assessments. It’s a compass, not a map.

How and when embodied carbon will enter the discussion remains TBD, but the White House is confident it’s not far off. “The process of doing analysis around embodied carbon is in its infancy, it’s more challenging to figure out,” says Clark. “But we are going to be engaging in a part two of this definition shortly.” In the meantime, Clark returns to the idea of market alignment and defers to “other certifications and design programs” that specifically cover scopes 2 and 3 emissions.

Heather Clark also happens to lead efforts on behalf of the White House related to the Buildings Breakthrough initiative that came out of COP28 last year, in which a collective of signatory nations pledged to make “near-zero” emissions and resilient buildings “the new normal by 2030.” Of the working groups that were conceived in the aftermath of COP28, the first to get up and running was given a mandate “to come up with a clear definition of what zero emissions buildings are. So, we are very much on track,” Clark says.

Once the definition is finalized, or near finalized (there is no ETA on when this might be), it will no doubt come in handy when representatives from the White House, DOE, and other agencies attend the Buildings and Climate Global Forum, happening in Paris this March. This forum will give Buildings Breakthrough signatories a platform to disclose just how they plan to abide their commitments to decarbonization, resiliency, and emissions reductions for the building sector.

For the foreseeable future, private markets, certification programs, and performance standards will continue to proliferate, for better or worse. Codes will be adopted, amended, or passed over. And ‘zero emissions’ in one part of the country will be construed differently elsewhere. We have enough problems without building science devolving into lexicology. So, perhaps a federalized and unilateral definition of something that should feel obvious—but clearly isn’t—is the smart play. According to the senior DOE official, “We see the definition as a framework that will offer designers and builders multiple pathways to influence the design and operations of buildings.”

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Justin R. Wolf is a Maine-based writer who covers green building trends and energy policy.