Source: Energy News Network
ARLINGTON COUNTY, Va. — It’s clear Amazon thought outside its own ubiquitous brown cardboard box when sketching blueprints for its second headquarters.
At a series of mid-June opening events, guests oohed at the pair of sleek, 22-story glass-paneled towers on the former site of a nondescript warehouse near the Potomac River. And they aahed at the adjacent 2.5-acre public park replete with art, a central green, a playground, and gardens flush with native plants and trees.
However, what has awed authorities at the U.S. Green Building Council is how dozens of carbon-saving measures woven into the complex will advance climate consciousness and energy conservation in the construction industry.
The 2.1 million square feet of HQ2 office space hums along with zero operational carbon emissions because it is powered 100% by renewable energy.
Minimizing reliance on fossil fuels aligns with the mega-company’s commitment to achieve net-zero emissions by 2040, a decade ahead of the Paris climate accord.
“When you get a large, high profile project like an Amazon, which jumps through hoops to innovate, it transforms the market,” said Wes Sullens, LEED director at the council. “This is an anchor project that can move mountains.”
Indeed, the council will be adopting some of Amazon’s innovations with concrete and other materials when it releases an update to its Leadership in Energy and Environmental Design (LEED) scorecards next year.
In the meantime, draft concepts of version five will be shared and reviewed in late September at Greenbuild, the council’s international conference and expo in its hometown of Washington, D.C.
Amazon is seeking LEED platinum certification — the most stringent of the building council’s four levels — for this first phase of HQ2, also called Metropolitan Park.
One of the drivers behind that push is Fernando Arias. He operates out of Clark Construction’s nearby McLean, Virginia, office as the director of sustainability. Clark and its contractors began strategizing about an ambitious carbon diet once Amazon selected the Northern Virginia site in 2018.
Arias, an architect, beamed when explaining that his team strove to exceed green building goals even as supply chains were severely disrupted when construction began with the onset of the pandemic in 2020.
For instance, the total project called for 200,000 cubic yards of concrete. That’s enough to fill the reflecting pool at the Lincoln Memorial six times.
Amazon specified in its contract that it wanted the carbon footprint of all concrete use at HQ2 to be 20% below the industry baseline. Arias helped to almost double that goal — achieving 37% — by meticulously targeting lifecycle emissions.
“I get a sense of pride” about HQ2 because “we’ve moved the needle on what to expect in the future,” Arias said. “It was Amazon’s climate pledge that spearheaded a lot of this.”
A sweeping staircase is one feature of a lower floor in Amazon’s HQ2. Credit: Elizabeth McGowan
Merlin is one of the two 22-storyglass-paneled towers on Amazon’s corporate technology campus in Arlington County. Its sister tower is Jasper. Credit: Elizabeth McGowan
‘These are not frou-frou green things’
Moving that needle required a single-minded obsession with the growing field of environmental product declarations, or EPDs for short.
Simply put, the declarations are reports that spell out the full-cycle environmental impact of a material or product over its lifetime. Those calculations quantify what the construction industry refers to as embodied carbon. Comprehensive reports track emissions generated from mining a particular raw material, transporting it, operating the kiln, furnace or other equipment to create the building material, then using it to build a road or structure.
Those details offer sustainable options for architects, engineers and designers. As well, the information allows manufacturers to openly market their carbon transparency.
Arias jokingly refers to the declarations as “nutrition labels for structural materials.” In all, his team relied on more than 60 EDFs, mainly to account for the Amazon project’s supplies of cement, steel and masonry.
Some of those EDFs are new and unique to HQ2 because Amazon was so intent on shrinking emissions. First off, the team’s overall approach to cement was hyperlocal. The cleared site in what’s locally known as Crystal City was roomy enough to include an on-site batch plant. That curbed transportation emissions significantly because it eliminated fleets of giant delivery trucks from area highways and neighborhood streets.
Relatedly, Arias and his Clark colleagues brainstormed with other specialists about the “cleanest” method for crafting cement from “ingredients” provided by nearby vendors.
For instance, they had to formulate how to efficiently boil the raw limestone so as to extract the cement that serves as the glue, or binding agent in concrete. Then, they had to balance what ratios of water, mineralized carbon dioxide, and sand and aggregate would create a mixture that cured correctly.
Cement might be a small portion of that recipe, but freeing it packs an enormous carbon punch, Arias said.
“This [region] has a lot of infrastructure in place to provide low-carbon concrete for construction,” he said, referring to the District of Columbia and neighboring counties in Virginia and Maryland.
Understandably, he didn’t want to share any trade secrets, but some of those new concrete-centric EDFs will be setting a higher bar on the Green Building Council’s scorecards.
“These are not frou-frou green things,” Arias said. “Low-carbon construction is not about using exotic materials. It’s a combination of humans being smart, making efficient decisions and buying locally.”
He’s aware that co-locating a cement batch plant isn’t possible for every construction project, but other low-carbon resources can be at a builder’s disposal.
Arias is intimately familiar with the Green Building Council’s guiding principles because he serves on a 10-member steering committee tasked with preserving the integrity of the LEED rating systems. Members are now devoting much of their time to upgrading LEED to version five.
It was fortuitous that plans for HQ2 in Arlington were taking shape as embodied carbon awareness was gaining traction in the industry. The project dovetailed with the launch of what’s called an embodied carbon in construction calculator. That tool, abbreviated as EC3, allows builders to dig into a database that compares carbon information across classes of most materials.
“The landmark year for all of this was 2019,” Arias said. “It really presented a fuller carbon picture.”
EC3 was devised by Building Transparency, a nonprofit based in Washington state dedicated to sustainability in construction.
That initiative, paired with efforts such as the federal government’s Buy Clean standard, is advancing low-carbon progress across the marketplace, he said.
EPDs help tame energy hogs
One reason the U.S. Green Building Council can even embark on the next iteration of its LEED measuring stick, version five, is because companies such as Clark push the envelope with HQ2 and similar exemplary projects.
“We can go farther than we would have otherwise,” Sullens said. “Over time, as more companies reach these rigorous standards, they get pulled into the mainstream and we can reach for the next level.”
The council first concocted a green building rating system 23 years ago because its members were alarmed by the industry’s carbon footprint.
An initial focus on new construction in the commercial sector has expanded to all building types, as well as neighborhoods, communities and cities. Reducing a building’s contribution to global climate change isn’t the only way an applicant can score certification points. Buildings also are scored on factors such as how they enhance human health and community quality of life, protect and restore water and biodiversity, and promote sustainable material cycles.
Today, it’s the most widely used green building rating system. Upward of 105,000 buildings have earned LEED certification around the world.
Still, buildings account for 39% of global energy-related carbon emissions, according to the World Green Building Council. Roughly 11% are from materials and construction practices, while the remaining 28% come from the energy needed to cool, heat and power them.
Version five of LEED will remain laser-focused on decarbonization, Sullens said, but will also address critical imperatives that include equity, health, biodiversity and resilience.
It’s crucial for the LEED scorecards to offer credits for innovative EPDs — environmental product declarations — because it spurs demand for better products locally, regionally and nationally, Sullens said. Knowing what’s achievable can lead to environmental- and health-related policy changes at the state and federal level.
Studies indicate that projects can reduce embodied carbon by 20% to 40% with negligible extra costs, Sullens said. He’s hopeful that continued progress with sequestering that embodied carbon means emissions will hover close to zero by 2050.
While EPDs had a head start in Europe, this country is catching up.
“Once emissions are disclosed, and producers realize, ‘Oh, our project is an energy hog,’ they want to do better,” Sullens said.
The concrete industry, while relatively new to the EPD game, has buckled down on addressing its outsize emissions.
“That industry saw the writing on the wall and knew it needed to get ahead of the curve,” he said.
Sullens noted that EPDs for concrete — and all other building materials — are not a one-size-fits-all proposition. Variables such as geography and the location of a manufacturer mean some declarations apply only to a certain region or local area.
“We can say that, overall, we want to reduce embodied carbon by 20%, for instance, but what is realistic?” he asked rhetorically. “Despite the climate crisis, a question is, ‘What will the market bear?’”
While lifecycle information about carbon emissions is widely available, smaller industry players are known to grumble about having to compete with more muscular and well-heeled competitors to earn their green stripes. But Sullens maintains that’s no reason to put the brakes on ingenious solutions instigated by the Amazons of the world.
Acquiring a LEED platinum ranking is no cakewalk. And that’s intentional.
“We don’t want to give points for standard practices,” Sullens said. “We want to reward those actors who are first at peeking around corners to come up with innovation.”
How Amazon’s HQ2 pushes the (building) envelope on embodied carbon is an article from Energy News Network, a nonprofit news service covering the clean energy transition. If you would like to support us please make a donation.
Full Article: Read More
