LEED Zero and 4.1: Learning to Love LEED Again
It’s been a while since a LEED update generated much excitement. Not like the heady days of 2009 when v3 was released, and project teams were lining up to get things registered because of the market power LEED was commanding.
Since then, enthusiasm for LEED has flagged across the board. Maybe it was because v4 took as long as it did to be released and was generally considered lackluster and behind even most local codes at that point, while people were starting to ask the question: what about bigger issues like decarbonization or net zero? Or maybe because Green Business Certification Inc. (GBCI) just wore everyone down with the impression of a frustrating certification and documentation process.
Regardless, when I opened up v4.1 and the LEED Zero overview, my expectations were on the low side.
New and improved
But the more I dug into it, the more I began to feel like the U.S. Green Building Council (USGBC) had been saving up all of the improvements that the industry so badly needed and packaged them up in a version that could be rolled out under the radar in the guise of a minor update.
Motivations aside, these updates are the best thing that’s happened to LEED since possibly its inception. The credits that needed fixing (e.g. Rainwater Management and Daylight) have been fixed. The codes have been updated to the latest ASHRAE code set (2016, reflecting IECC 2018, which many jurisdictions around the country are about to roll out this year).
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Net-zero not only became recognizable, but a whole new rating designation sprang into existence to address it and provide guidance, including what do with all of those buildings that are either too tall or too energy-dense to achieve net-zero energy onsite (see my previous post on this topic here). Zero Carbon incorporates transportation-related emissions (though not embodied carbon just yet). And the badly needed discussion about how to turn buildings into resources that support the grid’s transition toward higher and higher renewable-energy content has begun with the updated Renewable Energy credit—which now includes credit for entering into power purchase agreements for new renewable resources—and a new grid harmonization credit, replacing its v4 Demand Response credit predecessor.
Still some catching up to do
Does this address all of the possible changes that LEED needed to catch up with the market? Not quite.
There are still opportunities to integrate some of the health elements that WELL, Fitwel, and RESET have been successfully addressing, such as IAQ testing and monitoring, acoustics testing, active design, etc., or site-related elements such as integration of natural systems and connecting occupants with nature that the Sustainable Sites Initiative does so well.
But all in all, LEED 4.1 is a rating system that truly reflects what sustainable building best practices actually look like. And since USGBC is allowing for one-to-one credit substitutions, cherry-picking these improvements and weaving them into v4 projects is something that all project teams should be looking into.
For a full description of the v4.1 changes, see the LEEDuser tip sheet. The following is our take on the significance of some of the major changes:
Optimize Energy Performance
The biggest change is that the baseline ratchets up to ASHRAE 90.1–2016, which is on average a 16% improvement over the previous 2010 version (depending on building type and climate zone). In addition, in a major shift in the way we think about “building energy performance,” energy points under Optimize Energy Performance are now awarded in part based on annual greenhouse gas (GHG) reductions (in addition to the traditional annual energy cost reductions), which references a project’s eGrid region for grid GHG emissions factors, or EPA’s AVERT tool’s estimate of hourly emission offsets.
This means that if a project shifts to an all-electric HVAC system to eliminate onsite gas usage, while it may yield modest energy-cost reductions, it could yield significant GHG reductions if the local grid has committed to a decarbonization pathway. Further, the off-site renewables provision can be used to off-site a project’s GHG impact under this credit, so this could drive all projects to seek out power purchase agreements (PPAs) to enable them to reach 100% carbon reduction, and open the door to pursue the Zero Carbon or Zero Energy designations.
One of the most important additions in v4.1 is the updated treatment of renewable energy. It always bothered me that an urban project, or a mid- to high-rise project, or a project with no solar access couldn’t participate in the renewable energy credit in a meaningful way.
Now the renewable energy credit is broadened to include off-site renewable energy, and distinguishes between new and existing off-site energy, valuing a new off-site resource, higher than existing off-site resource (while onsite resources are valued the highest of all). Sadly, v4.1 still has an option for unbundled renewable energy certificates (RECs) and green power, and now up to three points are available for this option instead of two. That said, the thresholds for each point have increased significantly, so this will hopefully dissuade projects from pursuing this option and encourage them to instead seek out the more valuable PPA options.
All of this means that all projects should now be thinking about the procurement options of their energy supply, and sourcing any supply that can’t be produced onsite from PPAs for renewables off-site – and ideally from new developments.
The old Demand Response (DR) credit has gone away, and it is replaced with a much broader and well written approach to turning buildings into utility resources. Project teams are now encouraged to become aware of what the grid is doing and to utilize storage or demand response to adjust to those grid conditions. This is going to become a bigger and bigger deal for grid resiliency in the age of renewables, especially in places that are already starting to see a “duck curve,” providing guidance for buildings to deploy renewable energy, demand response, and storage in a way that creates benefit beyond the building.
Recognizing that the future of full decarbonization relies on electrification of both HVAC systems and vehicles, the Green Vehicles credit under v4 is replaced with a new Electric Vehicles credit under 4.1. Not only does this new credit allow for the installation of charging stations, but it also provides a path for providing EV charging infrastructure. At this point, no building should be built without EV charging infrastructure, so this is a great addition.
When version v4 came out, many project teams quickly realized how difficult it was to achieve both the sDA (daylight quantity and distribution) and ASE (glare) requirements to earn any points. Originally, ASE was set to a maximum of 10%, which precluded many projects from getting anywhere with the credit.
Along the way, an addendum was released, effectively raising the ASE bar to 20%, but now in v4.1 the ASE requirement is dropped altogether, replaced with a requirement to provide a narrative on how glare is addressed in those spaces that exceed the original 10% threshold. This effectively gives teams more flexibility in deciding which spaces need glare control and how to go about achieving it.
It does leave the door open for projects creating good daylight design and then occupants leaving the shades down all the time, but that should prevent a project from earning the credit. In addition, the credit’s minimum sDA requirement drops to 55% for one point under v4.1, making the credit more accessible for a wider variety of building types (including downtown offices that may have had less flexibility in terms of massing).
This was one of my least favorite credits under v4. For one thing, it was vaguely written, requiring teams to “manage” rainwater, when what they meant was infiltrate or capture and reuse rainwater. Also, it effectively meant that projects needed to either infiltrate the 95th percentile rain event (1.1" in Denver, for example), which was a non-starter for most urban projects, or capture and reuse that water. There was no opportunity for treating stormwater onsite via best management practices or natural systems (managing rate and quality) if that water eventually drained into the storm system.
While the 4.1 update doesn’t address all of these points, it at least clarifies what is meant by “managed”—“infiltrate, evapotranspirate, or collect and reuse”—and it lowers the threshold for one point to the 80th percentile rainfall event (0.6" in Denver), which should make the credit more achievable for many projects.
There are some major changes to a number of other important credits as well, and these are summarized in the LEEDuser tip sheet here.