It’s been a little over a year since the U.S. Green Building Council (USGBC) first announced an update to Leadership in Energy and Environmental Design (LEED), the most widely used green building program in the world. What’s new with LEED version 4.1? What are the goals? And what can we learn from some of the projects that have already certified?

Melissa Baker, senior vice president for technical core at USGBC, says that the update is designed to equip project teams with the right tools to better understand how their buildings are performing, to demonstrate that all the sustainability goals are met, and to identify areas for improvement.

“We wanted to make the rating system more accessible,” Baker says. “Establishing stepping stones, getting people [to use] credits that haven’t had much uptake, where we might have wanted to see uptake. Also, taking the market feedback that we’ve received and incorporating that while maintaining leadership.”

One major element of LEED v4.1 is further reinforcing that performance is the future, Baker says. “We don’t want people to stop at new construction certification—although we want that rating system to work well—but we want people to track and enter their data and get the continued recognition through recertification,” she says.

USGBC has announced that all buildings and projects that have previously been certified under any version of LEED can recertify to the latest version, 4.1. There’s now a pathway for many of the more than 76,000 certified and certified projects worldwide to gain additional recognition and demonstrate continued performance. To recertify, a building must show a year of data that demonstrates its performance is improving by reducing energy and water usage, waste production, transportation, and promoting human health and wellness.

While pursuing recertification, projects gain the added benefit of putting numbers to their sustainability investments and efficiency upgrades. The performance-based building recertification is achieved using Arc, allowing building managers to input data and track their performance, streamline documentation and move projects through certification faster.

Carbon is now a metric

One area where LEED v4.1 is raising the bar is energy conservation. For new construction, the minimum energy performance prerequisite and credit reference ASHRAE 90.1 2016, while retaining cost as a key metric and adding a greenhouse gas emissions metric for the first time. Significantly, USGBC also chose carbon, alongside source energy, as a metric for the Operations and Maintenance rating system.

“Really this is the first time we’ve had carbon as a metric,” Baker says. “It’s important but it’s also going to be an interesting learning curve for the market because not many people are really using carbon metrics yet. I think people are excited about it. I think there’s recognition that there’s a need to start to understand overall carbon impact. It ties in to the power grid, ties in the efficiency of the buildings, but it’s broader than just the building. It’s the community.”

The decision to recognize carbon and push builders toward reducing their emissions footprint is a nod to the greater availability of more affordable energy efficiency technology, cheap renewable energy coming in the form of wind and solar projects, and renewable energy credits offered by power utilities.

LEED 4.1 also attempts to address a complicated new area of efficiency and building construction, sometimes called embodied carbon. It’s an effort to quantify the amount of carbon that’s emitted during each step in the supply chain—from the building materials to construction equipment, transportation, and the many other steps that go into constructing a building.

In a previous version of LEED, USGBC began to look at the amount of emissions baked into construction of a building through its Materials and Resources category, but Baker said USGBC is trying to make the credits more accessible and usable in this latest update.

“We understand that the full lifecycle of the building is critical—especially given the amount of impact that happens during early phases of new construction,” Baker says. “Everyone’s trying to get their arms around how to calculate embodied carbon, how you get the data that feeds into it. It’s definitely an interesting point of discussion and obviously very important. If you map the carbon impact of a building, embodied carbon in the materials and the construction of the building, it is a huge part of that footprint.”

New and improved

Beyond calculating the footprint of building construction, USGBC now offers a new certification for previously LEED certified buildings that achieve net zero carbon emissions, energy, water, or waste. LEED Zero certification builds on other LEED rating systems verifying the achievement of net zero goals and signaling market leadership in the built environment. Baker says pushing carbon reductions at the organization level became a more pressing goal after the latest report from the Intergovernmental Panel on Climate Change released last fall, which painted an even more extreme portrait of the risks posed by climate change than previously thought.

As an additional example of the changes projects will see in LEED v4.1 for new construction, in previous versions of LEED, there were difficult thresholds for rainwater management for new construction to meet—especially in big cities.

LEED v4.1 has adjusted some thresholds based on market feedback. “It’s a really important environmental issue,” Baker said. “But especially if you have a zero-lot-line, people just couldn’t meet the thresholds. We’re really looking at low-impact development and trying to retain water on site.”

Another big goal of 4.1 was to accelerate the development cycle for the rating system, which in the past has taken between three and five years. With v4.1 the time frame was compressed; within a year the system will be fully available in beta.

President and CEO of USGBC Mahesh Ramanujam says that for a quarter century the organization has worked to make communities healthier and more sustainable—recertification has always been a key part of the LEED mission. “We are focusing on the areas where we can make the biggest impact to improve the standard of living globally— the performance of our buildings,” he says. “That’s why we want all LEED projects to continue to demonstrate leadership and ensure they are actually providing real benefits to the people who inhabit them.”

Chicago’s Willis Tower achieved LEED Gold certification under v2009, as well as recertification with LEED v4.1 using Arc, during a massive renovation project. Upgrades included an improved LED lighting system and improving the buildings heating and cooling systems.

Chicago’s Willis Tower achieved LEED Gold certification under v2009, as well as recertification with LEED v4.1 using Arc, during a massive renovation project. Upgrades included an improved LED lighting system and improving the buildings heating and cooling systems.

Willis tower v2009 vs. V4.1

In late 2018, Willis Tower achieved an initial LEED v2009 certification as well as the recertification tasks using the latest update to the rating system, LEED v4.1, which emphasizes performance and tracks progress through the Arc platform. The process began during a half billion-dollar building renovation, the largest in the building’s 43-year history.

The Willis Tower upgrades included installing an improved LED lighting system with controls to reduce energy use, improving the building’s heating and cooling to better control temperatures and consume less energy, and introducing new fan gearboxes and fan blades, along with the installation of new variable frequency drives to all four of the building’s cooling towers (this will reduce power consumed by the cooling towers by 20 percent). Additionally, the building installed 450 low-flow sinks and 650 toilets and urinals to save an estimated 11 million gallons of water every year, a reduction of 30 percent building-wide.

The renovation also added 300,000 square feet of new space for retail shops, restaurants, and other entertainment and a 30,000-square-foot outdoor garden. David Moore, the senior vice president and portfolio director for EQ Office, which is owned by Blackstone’s real estate funds, says that Willis Tower is a tourist and entertainment destination and a workplace for 15,000 people. “As we redevelop this iconic tower, we’re making a conscious effort to find ways to improve energy efficiency and reduce our environmental footprint. Earning LEED Gold certification is a credit to our entire team for their hard work,” he says.

Rivion, a Wisconsin-based energy-consulting firm, helped Willis Tower with the energy savings plan. Samantha Longshore, a senior solutions consultant with Rivion, says it was really interesting to see the building scored higher in version 4.1, which Longshore says made sense based on what the team was seeing on site. “We spent a lot of time at the building before moving into LEED, looking at the building in the ENERGY STAR portfolio manager, doing night audits at the building, looking at the metering system, and we felt that it was running well,” she says. “The operations were efficient and they’re doing a lot of upgrades. We feel that score in Arc that resulted in the LEED v4.1 recertification was representing what we were seeing on site.”

Longshore says another major difference in the experience between the two versions is that while you have to do the recertification for 4.1 more often, it’s an easier lift. The surveys are simplified and there is a scaling effect based on occupancy. In other words, it’s easier to achieve all the needed responses from employees in the building. Longshore says that her team spent a lot more time trying to get the number of needed responses for version 2009.
“Along with the smaller lift every year, we see a big benefit for project teams checking into these operations once every year, rather than once every five years,” Longshore said.

Longshore acknowledges that LEED 4.1 is a different system with a new strategy, and it can take a bit of time to learn the new system. But she’s finding it useful to immerse herself in the information. “To see indoor air quality readings as opposed to looking at calculations and based on those numbers trying to balance and get a particular number—it’s neat to see what’s occurring in different spaces.”

She adds that it is a unique way to troubleshoot problems. “It is interesting with LEED v4.1 to see what’s on the ground.”

Samantha Longshore is a senior solutions consultant with Rivion, an energy-consulting firm, which helped Willis Tower with the energy savings plan. David Moore is the senior vice president and portfolio director for EQ Office.

Samantha Longshore is a senior solutions consultant with Rivion, an energy-consulting firm, which helped Willis Tower with the energy savings plan. David Moore is the senior vice president and portfolio director for EQ Office.

What’s next for LEED: LEED v4.1, recertification and LEED Zero