LEED v5 Preview #3: Energy and Operational Carbon in BD+C
This is the third post in a series on LEED v5; it focuses on new construction. Part One provides an overview of the philosophy and underlying structure of all the LEED v5 rating systems. Part Two provides an overview of the O+M draft. Part Three looks at energy and operational carbon in BD+C and ID+C. Part Four is about the proposed building design and construction EQ approach.
What’s the most important thing the next version of LEED needs to do?
- Decarbonize the sector
- Center social equity
- Integrate resilience
- Eliminate hazardous chemicals
- Support the power grid
- Ensure occupant well-being
- Create community connections
- Protect native ecosystems
Right in one! The answer is obviously “all of the above.” But you do see the problem, right? Look at the task we’ve set ourselves up there. Then, please spend up to three minutes on each of the items below.
- Think about how far we’ve come. Take your time.
Huh, that was quick.
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- Remember all the reasons we’ve come up short.
I said three minutes! Pencils down!
- Fix it all.
Now you understand what it’s like for the U.S. Green Building Council (USGBC) as staff members and many, many committee volunteers collaborate to develop LEED v5. (By the way, the existing building standard is already drafted.)
Egos aside, please
Luckily, all those folks have made a commitment to do the best they can. And they’re also asking for more help. SVP Melissa Baker issued this invitation during the v5 overview session at Greenbuild: “Try it. Test it. Break it so we can fix it.”
The very next session I attended featured USGBC’s principal climate advisor, Laurie Kerr, to introduce the framework behind the Energy & Atmosphere (EA) credit category for design and construction (that encompasses both BD+C and ID+C). Kerr began with this vision statement: “LEED v5 will drive the built environment toward a low-carbon future that is equitable and resilient and promotes the wise, safe utilization of all resources.”
Golly, that seems to be hitting 1 through 8 of my pop quiz pretty well in one tidy little sentence! But to make it all happen, we’ll need to work together in good faith. Even when it frustrates us and makes us grumpy. Even when our own obviously great ideas and pet priorities aren’t the ones that ultimately get adopted.
“It is not about the glory; it’s about the ripples,” said Ayana Elizabeth Johnson, fittingly, at Greenbuild’s closing plenary. “Set your egos aside, collaborate, and change the world. We need you.”
Let’s talk energy
Kerr spent a good long time reviewing the history of green building—and she looked back 50+ years (not 30), quite a ways before USGBC or LEED. In the beginning, it was all. about. energy. (BTW, Jimmy Carter is still with us. Celebrate with some ice cream. And put on a sweater!)
But energy … it’s so 20th century. Now it’s all about carbon, right?
Weirdly, it’s not.
“Efficiency has been the name of the game,” said Kerr. “And we’ve done pretty well with it.” Not that long ago, she reminded us, the U.S. was expecting to need 500 new power plants to meet exploding demand. But due to efficiency gains in buildings, “electricity use sort of flattened.”
Nowadays, virtually all the new power on the electrical grid is coming from renewables. (Yes, they’ve been cheaper for a while now.) This is why you hear everyone talking about electrification: as the grid jettisons fossil fuels, and heat pumps and integrated onsite storage options get better and better, the grid is becoming an energy source that’s far, far superior to gas-powered furnaces, boilers, ranges, and water heaters.
So what’s the problem? Just electrify everything!
Well, no. Without a requirement for energy efficiency, “the grid we would need to build out would be huge,” according to Kerr, “especially because of peak loads from heating and cooling.”
A familiar(?) energy + carbon approach
At that point, committee member Amy Pastor introduced the probable framework of the entire EA category under development for BD+C and ID+C, with prereqs and credits addressing:
- Beneficial electrification (probably a credit at first)
- Energy efficiency (credit and prerequisite both)
- Commissioning, metering, and reporting (credits and prerequisite both)
- Refrigerant emissions and management (unclear if required, but Kigali aligned)
- Renewable energy (credit)
- Grid harmonization (credit)
Note that the only phrasing on that list that comes close to explicitly addressing greenhouse gases is the word “emissions” in the refrigerant category. But that’s okay because this framework is managing carbon and energy simultaneously in multiple ways through electrification, renewable energy, and grid harmonization.
Since those are all likely to be credits and not prerequisites, though, the part I want to call out especially is energy efficiency. That’s because it is:
1. Actually a dual approach (energy + carbon) even though it’s not expressed that way on the list
2. Not new—or not exactly
The approaches under consideration, according to Pastor, can already be found as v4 and v4.1 pilot alternative compliance paths, or ACPs, which USGBC introduced in February 2023 (hey, that means you can try them out on any v4 or v4.1 project right now!):
- PC160—Electrification ACP: Prescriptive Path
- PC161—Electrification ACP: Energy Simulation Performance Path
The prescriptive path under consideration
The goals of PC160 are clearly described in the credit language. Buildings must:
- Have low peak HVAC loads
- Reduce all the energy loads not associated with space heating and cooling
- Be designed and constructed to operate without burning fossil fuels onsite “except at very low outdoor temperatures”
- Include renewables
Pastor promised the forthcoming draft of the prescriptive path would involve “no complex math” and would track with ever-advancing versions of ASHRAE 90.1.
Projects pursuing this prescriptive path would achieve points for “further reductions in emissions and in peak heating and cooling reductions,” Pastor said—earning roughly one point for each percentage reduction in lighting loads or HVAC, and other points associated with electrification and onsite renewables.
The performance path under consideration
The goals of PC161 are the same as the ones listed for the PC160 prescriptive path above. But the execution definitely involves “complex math.” There are two metrics referenced in the pilot ACP language:
- Demand-adjusted energy: This is the only option available to v4.1 projects, and that may or may not be an indicator of where v5 will intially land. If you’re in the U.S., Cambium is involved, and if you don’t know what Cambium is, read reason #1 of these eight reasons why net-zero energy isn’t the real goal. The Excel spreadsheet provided by USGBC with the demand-adjusted-energy calculator explains this metric in more detail, and I’m pulling that out into its own section below because … it’s a lot.
- Total greenhouse gas emissions: Again, note that this option is only available to v4 (not v4.1) projects. There are multiple sources for the required data, depending on project location, but the upshot is that you’re supposed to use the most current grid decarbonization estimates you can find. In the U.S., this is likely to be either the U.S. Environmental Protection Agency’s most recent guidance or the assumptions used for the “Tier 2” calculation in the v4.1 Renewable Energy credit. (Since “Tier 2” implies not the power grid at all but rather offsite renewables that would allegedly not exist without your snowflake of a LEED project, I’m just going to send you here and awkwardly flop out of the deep end onto the side of the pool and cough a bit, if you don’t mind. Yes, I’m fine, thanks. Please stop pounding my back so I can stand up and find my way back to the prescriptive path?)
Who or what is demand-adjusted energy?
Glad you asked! According to the notes tab of the LEED Hourly Cambium Demand-Adjusted Energy Metrics Calculator, these are the things the “demand-adjusted energy” metric is designed to incentivize:
- Energy efficiency
- Efficient electrification
- Peak-load reduction
- Grid harmonization
Sounds great, but to accomplish that, the metric “adds the site energy consumption for the baseline and proposed design for electricity and fuel used onsite to a ‘demand adjustment’ for electricity.”
Are you with me here? Because I’m not sure I am.
But seriously, I’m starting to think my friend Josh Radoff had a point when he called grid harmonization an “unnecessary complication.”
However, he really only meant that for us schlubs who don’t get it. His argument in that series was for a comprehensive standard that people like me can understand. And that’s why he also added that grid harmonization (or optimization or interactivity or whatever term you prefer) “is important, and I am an advocate for the building industry moving in this direction.”
So I say this. Early adopters, you go for it! This is what LEED is all about: leadership.
But me and mine? We’ll just … poke a bit more insulation into this little gap.