By Adoga Michael Oyi
How the Smithsonian’s newest museum set the bar for sustainability in architecture
The museum’s situation on the National Mall gives it access to ample water and sunlight. (Martin Stupich)
Ever since its grand opening in September of 2016, the National Museum of African American History and Culture (NMAAHC) has stood as a gleaming bulwark of a vital part of America’s national story. No mere receptacle for artifacts, the building itself teems with historical resonances. Its bronze-hued corona echoes traditional Nigerian designs, the transparent walls of its entry level set it in conversation with the nearby Washington Monument and Lincoln Memorial, and the wending ramp of its lower floors reflects the unsteady path of progress throughout history.
With all these allusions to pick apart, it can be easy to miss another striking element of the museum: its emphasis on eco-friendliness. Subtly and in many cases quite cleverly, the design of the museum avoids resource waste without diminishing the visitor experience or imperiling its artifacts. Making an environmentally conscious building required commitment from the outset, and now that commitment has paid off: on April 16, the African American History Museum was officially awarded a Gold certification by the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) program . In the architecture business, this type of recognition is tantamount to an eco-Oscar.
There are four rankings LEED awards green buildings via a rigorous scoring system: basic certification, Silver, Gold and Platinum. For smaller buildings, reaching higher levels of self-sufficiency isn’t terribly hard, but for a hulking museum like NMAAHC, attaining Gold status constitutes a real achievement.
Phil Freelon , the museum’s lead architect, knew a thing or two about green design going in: prior to the project, he had been responsible for a pair of Gold-certified libraries in the D.C. neighborhoods of Anacostia and Tenleytown. But NMAAHC presented fresh hurdles. “In a museum,” he says, “you have environmental standards that have to be met for humidity standards and temperature because of artifacts and organic material that could degrade if you’re not controlling humidity and temperature precisely.” Even after hours, preserving the artifacts is of paramount importance—and preserving artifacts takes energy.
In the early stages of the design process, Smithsonian funding for eco-friendly features in NMAAHC was uncertain. A broad Smithsonian directive expressing a desire for green development had been issued toward the end of 2006, but those working on the NMAAHC concept in the months immediately following could not be sure of exactly how much financial leeway they would receive. So they got crafty.
One of the leading advocates of this directive was
Brenda Sanchez , an accomplished architect who had signed on with the Institution in 2004. Like Freelon, she was committed from the start to incorporating sustainable building practices into the Smithsonian’s mission. She blueprinted her first sustainable house in 1991, before LEED was even founded, and she had learned quite a bit over the years about designing responsibly on a tight budget.
At the heart of Sanchez’s (and Freelon’s) approach to the museum was the principle of “passive design,” i.e. the art of minimizing a building’s environmental footprint without going out of one’s way to install any high-tech (and costly) add-ons.
Passive design began with NMAAHC’s compact, boxy shape. “If it’s a compact building form,” says Sanchez, “there is less use of energy for both heating and cooling.” The fact that most of the museum is subterranean also plays a vital role. “We have a limitation in this city that you can only go so high, but we used that to our advantage,” she says. “We have 60 percent of the building below ground, so we have the whole grounds acting as an insulator for the history galleries that are below.”
Once the museum designers got the go-ahead to implement active eco-friendly design features, rooftop solar cells were an obvious choice. (Martin Stupich)
To keep exhibits above ground safe from damaging sun, Sanchez and Freelon implemented a nested layout. “The building was designed as a matryoshka doll,” Sanchez says, “a box within a box within a box.” Sensitive exhibits were kept to the heart of the museum, dually shielded by the majestic exterior corona and a layer of glass beneath.
Freelon explains that the corona’s opacity is deliberately inconsistent, allowing sunlight to enter where it’s welcome and blocking it where it’s not. “Some of the panels are letting in more light, others less,” he says. “Those were intentionally placed to shade certain areas or let more light in in others.”
One of the shrewdest techniques Sanchez and Freelon employed to regulate the museum’s exposure to sunlight centered on the deciduous trees along its western flank. “In the summer, those trees shelter the building from the sun’s rays,” says Sanchez. “But in winter, because they’re deciduous, they have no leaves, so then they allow the sun to come in and warm the spaces.”
Once the museum designers had done as much as they possibly could for sustainability within their original budgetary constraints, the Smithsonian awarded them additional funds to go all-out and incorporate active features to supplement the passive design work they had already done.
One active feature Freelon is quick to call attention to is the battery of solar cells up on the roof of the museum. “That’s a flat roof,” he says, “and upon that roof you have an array of photovoltaic panels, which gather sunlight and convert it directly into electricity.”
Incoming sunlight is manipulated in other ways too. Freelon points out the presence of north-facing light monitors, which capture the pleasant, diffuse sunlight coming from that direction and redirect the natural light to portions of the museum that need it. “In the administrative offices,” Freelon says, “you don’t have to be right next to a window to have natural light come in.”
The museum is equally remarkable for its water management as for its handling of light. Owing to its site, the museum has ample groundwater to work with, and it receives appreciable rainfall as well. Sanchez and Freelon have exploited this water to the fullest with an underground dual-cistern system.
“In one cistern, we filter the water,” Sanchez says, “and then that water gets reused elsewhere in the building.” Annually, she estimates the museum is saving 8 million gallons of water thanks to this recycling. Some of that goes toward mundane operations like flushing toilets (“Eighteen gallons a day just for that!”), while much of it helps with irrigation on museum grounds, keeping the museum’s lawns, trees and shrubberies in fine form.
Brenda Sanchez notes that the “porch” of the museum, in addition to serving a symbolic purpose, creates a cool and inviting microclimate for visitors.
The other cistern absorbs water from the earth once it’s saturated in a storm, then gradually releases that water back into the soil afterwards to ensure plants in the area aren’t missing out on any. Often, this vault will accumulate significant excess water, which the museum routes into municipal pipelines. Sanchez says NMAAHC’s system is saving Washington, D.C. roughly a million gallons of water a year. (It’s not for nothing that LEED awarded the museum a perfect score in its water category.)
There are many other technological marvels built into NMAAHC that one could single out—not the least of them is a state-of-the-art, ultra-high-efficiency HVAC system. But what Sanchez and Freelon seem to agree is the signature sustainable feature of the museum is actually one of its simplest, a holdover from the earliest days of passive design creativity. Both designers have a special fondness for the overhung entrance of the museum, affectionately termed “the porch.”
In addition to shielding the transparent entry level of the museum from the sun’s rays, the porch interacts with the museum’s slender oblong fountain to create a welcoming oasis for visitors just outside the front doors. “When the south breezes come through the water,” Sanchez says, “it cools the water, goes underneath the porch, and creates a microclimate. It can be up to ten degrees cooler there than anywhere else on the site.”
What the designers find so compelling about the porch is that it explicitly unites the environmentalism of the museum with the subject matter of African-American history. “We have a porch because, philosophically, the museum wanted to have a porch to serve as a beginning, an entrance, a welcoming to the people. In the South, you have a porch so that you can have the shelter and receive people and be welcoming.”
For Freelon, the porch brings out the larger connection of the mission of sustainability to the African-American experience. “In the African-American culture, we’re used to making something out of nothing and doing more with less,” he says, “whether it’s the food we eat or the materials we use in construction. So this building is expressive of that.”
Freelon, Sanchez and all others involved in the design of NMAAHC view their LEED Gold certification as a hard-won badge of honor. Freelon believes sustainability is the new norm in architecture, and that many more innovative buildings like the African American History and Culture Museum are near on the horizon.
“Virtually everyone in my profession is attuned to this issue,” he says, “and we’re doing all that we can as an industry to safeguard the environment and design buildings that are responsive and do not degrade.”
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