California has rolled out its amended Green Building Standards Code, commonly referred to as CALGreen. Starting this past July 1, CALGreen’s new embodied carbon requirements went into effect, mandating reductions in upfront emissions associated with non-residential buildings for new construction and major renovations larger than 100,000 sq. ft., as well as schools larger than 50,000 sq. ft.

There are three pathways to compliance: building reuse, whole-building lifecycle assessments (WB LCAs), and a prescriptive path that relies chiefly on environmental product declarations (EPDs). (Comprehensive resources on the building code can be found here.) Further, each of these mandatory paths includes voluntary provisions designed to increase overall reductions beyond what’s required. For example, baseline requirements for the reuse path state at least 45% of the building’s structure and enclosure be reused. Voluntary add-ons bring that percentage up to 75% (Tier 1) or 75% plus at least 30% of interior non-structural elements be reused as well (Tier 2).

Pushback on the amended code has been minimal thus far, likely because California has been ahead of the curve—at least in the U.S.—on matters of energy policy and renewables for decades. As Webly Bowles, the former associate director of codes & policy at New Buildings Institute (NBI) notes, “The biggest criticism of CALGreen has been that it’s too easy to achieve. Most of that criticism comes from experienced professionals who have years of experience working with low-carbon products.”

In California, the onramp for making embodied carbon reductions a requirement in the commercial sector had already been built. Statewide emissions reductions have been standard operating procedure for almost 20 years, starting with Governor Schwarzenegger’s 2005 executive order to establish GHG emissions targets. However, some of the finer points within CALGreen’s compliance paths have been revisited and concerns raised over just how aligned the three pathways are.

Questioning the prescriptive path

As Jack Rusk, co-founder of C.Scale, recently observed, the first two pathways—building reuse and a 60-year cradle-to-grave WB LCA—are noteworthy for mandating some quantifiable reduction from baseline. The third, however, prescribes the use of materials with Environmental Product Declarations (EPDs) be within 175% of the industry average global warming potential (GWP). “It’s confusing that the first two represent a GWP reduction from business-as-usual while the third represents a potential 75% increase,” Rusk noted in a LinkedIn post.

I caught up with Rusk over Zoom to get his take: “When buildings are being built, everybody’s looking for the least expensive pathway, right? Or at least the thing they’re most comfortable using with buildings over 100,000 square feet,” he says, alluding to the inherent popularity of using prescriptive pathways in California. These are “sophisticated contractors,” he says, “and if you’ve done a LEED building, then you know how to gather EPDs … It’s become clear this is clients’ preferred pathway.” (LEED has been baseline in California since 2004.) “Now, the focus must be on “tightening those [GWP] limits over time.”

Rusk’s intent is to point out an evident discrepancy in the pathways, not to besmirch the merits of the building code. “I’m really happy [CALGreen] exists,” he says, before pivoting back to his overarching concern. The threshold for the prescriptive path “is almost two times the industry average. This means you can have relatively high emitting products.”

Prioritizing accessibility

Despite California’s impressive climate record of improving air quality, decarbonizing the built environment, and transitioning its grid to renewables, this doesn’t necessarily make every developer, contractor, architect, or code official an expert on all-things green building.

Anish Tilak, manager of carbon-free buildings with RMI, says CALGreen is just now “introducing embodied carbon reduction to a broad swath of the private market.” Tilak’s inside knowledge on the matter extends to RMI’s role as a consulting author for the amendment during the 2022 intervening code adoption cycle, along with USGBC and NBI. “There are two intents behind the code,” he says. “One is to make a pretty accessible set of compliance criteria; and [the second is] to have options so practitioners can choose the best path for their project, rather than being overly prescriptive.”

Tilak highlights the importance of “optionality.” He likewise stresses, in the context of any alleged discrepancy in the pathways, how the prescriptive path is key to “getting the EPD submittal process integrated into all construction projects.” Just the act of specifying materials with EPDs “results in emissions reduction” and a reduction in GWP, he says. “In my estimation the paths are equivalent, even though the way they’re written might not imply that.”

The prescriptive path was also designed to be aligned with the Buy Clean California Act, which requires limiting embodied carbon in building products for state-funded projects, with the important addition of concrete. Also worth noting is the prescriptive path has Tier 1 and 2 voluntary steps that gradually reduce the GWP limits for industry wide EPDs. And subsequent reviews of the Buy Clean Act and the code cycle offer the promise of further reductions within CALGreen’s compliance paths, or possibly voluntary measures becoming mandatory. Another onramp.

“There is an adjustment period for the whole compliance community to incorporate this into their practice—that’s a big part,” says Amie Lewis, associate director of codes and policy at NBI. “This might be easy for architects and general contractors who are already working on big, complex projects, but it’s entirely new to the code compliance community.”

Lewis also highlights the importance of bringing California’s building departments on board gradually. “Training takes time,” she says. “We have 540 jurisdictions.”

Of course, this doesn’t even begin to consider other jurisdictions and companies around the country that will inevitably be impacted by CALGreen’s embodied carbon mandates. Even if those entities’ practices don’t have any direct ties to California (which remains the world’s 5^th largest economy), there’s a good chance they do indirectly, accounting for longer supply chains. As California goes, so does the rest of the U.S. In due time, CALGreen impacts (almost) everyone’s bottom line.

Demystifying the code

CALGreen’s 100,000-square-foot baseline for commercial projects is admittedly generous, at least as far as California is concerned. Lewis confides that during the intervening code cycle, the proposed minimum for non-residential buildings was 50,000, but underscores that the ensuring compromise “got our foot in the door this cycle … it’s a starting point.” A few disagreements notwithstanding, there is consensus among the code’s authors that the benchmarks currently in place are for the best, at least for now.

“To frame the project goals in ways that feel familiar, you need to demystify what the requirements are,” Lewis adds. Indeed, codes and standards can appear daunting to the uninitiated. But when performance requirements are presented as a checklist of best practices, they arguably become more palatable. “It’s about getting the market familiar with it.”

There is little doubt that new stringencies will come to bear, and numbers will go down, in future versions of CALGreen. Ideally aiding those updates will be the EPA’s newly released Label Program Approach, designed to help federal purchasers identify low embodied carbon construction materials. This program should help calibrate the measuring sticks by which EPDs are deemed good versus better within a specific category.

“Yes… and”

Discrepancy or not, a seldom cited benefit of CALGreen’s new embodied carbon compliance paths is that it’s not necessarily an either/or proposition. Pathways can be combined. For his part, Rusk considers how each of the pathways are interrelated, or at least should be. When it comes to embodied carbon solutions, he proclaims his favorite type of answer is “yes, and.”

“We need building retrofits. We also need to make sure they are low carbon building retrofits, and we need low carbon new construction. Maybe you do that with an LCA, and we need that documented with EPDs.” To his point, building retrofits on their face appear to be a climate-friendly alternative to new construction, but meeting a 45% baseline doesn’t tell the whole story, nor does procuring product- or factory-specific EPDs for steel, ready mix concrete, and other items.

“We need low carbon products in the context of low carbon buildings,” Rusk says. “We can walk and chew gum at the same time.”

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