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Architectural Crown Jewel

Marcy Marro, Editor, Posted 02/01/2017

Bronze scrim gives a distinctive look and strong presence to a symbolic landmark on the National Mall

Smithsonian National Museum of African American History and Culture, NMAAHC 

When former President Barack Obama spoke at the dedication of the Smithsonian National Museum of African American History and Culture (NMAAHC) on Sept. 24, 2016, he mentioned how the towering glass and the artistry of the metalwork is a sight to behold, but it is beyond the majesty of the building that tells the larger story of its significance. The museum tells the story of the African American experience, while celebrating achievements in art, history and culture.

Located adjacent to the National Museum of American History and the Washington Monument, the NMAAHC occupies the last available spot on the National Mall in Washington, D.C. The museum was designed by a collaboration of four architecture firms called Freelon Adjaye Bond/SmithGroupJJR (FAB/S). The Freelon Group (now part of Perkins+Will), Research Triangle Park, N.C., served as the architect of record and design team leader; Adjaye Associates, London, led the building design; Davis Brody Bond, New York City, developed the below-grade areas of the museum; and SmithGroupJJR, Washington, D.C., was the associated design/construction architect.

Designed to achieve LEED Gold certification, the NMAAHC is considered the most sustainable Smithsonian museum ever built. The 397,000-square-foot museum sits on 5 acres and has 10 floors--five above ground and five below--housing exhibit galleries, administrative areas, theatre space and storage facilities for the collection, which includes approximately 33,000 pieces of artwork and historical objects. The museum showcases historic milestones in African American history and everyday achievements of the individuals who have contributed to shaping American culture.

Hal Davis, FAIA, senior vice president, cultural studio leader emeritus at SmithGroupJJR, led the firm's work during the eight-year design and construction process. "The NMAAHC is clearly distinctive and quite different from the other museums on the Mall," he says. "Other Mall museums are stone or brick. This one expresses a totally different presence. It changes with the time of day and the weather. I think that provides a vibrancy missing form the other museums."

 

Smithsonian National Museum of African American History and Culture, NMAAHCDistinctive Form

Creating the museum's distinctive form, the bronze-colored cast-aluminum corona draws on familiar imagery from both African and American history. Inspired by the Yoruban Caryatid, a traditional wooden column that features a crown or corona at its top, the three-tiered, inverted step pyramid shape reaches 85 feet high. The building form and materiality express faith, hope and resiliency, while closely matching the angle of the Washington Monument's capstone. And, the Washington Monument's stones are used a reference for the NMAAHC panel proportion and pattern.

"The angle used for the corona is 17 degrees, the same as the slope on the top of the Washington Monument," Davis explains. "The upturned slope is also indicative of raised arms and hands in celebration, which is important in the tiers relationship to the galleries above grade that celebrate the achievements of African Americans to the culture of this country."

Enclos Corp., Eagan, Minn., was the design-assist contractor on the project, providing services in conjunction with Cleveland-based Northstar Contracting Inc. for the façade, including the glass curtainwall, architectural exposed structural steel (AESS) support system, cast-aluminum painted bronze corona panels, skylights, metal panels and storefront systems.

The 250,000-square-foot façade is made up of a latticework of 3,600 bronze panels that recall celebrated historical patterns by black ironworkers in the South. The exterior panels evoke ornate ironwork designs still visible in Charleston, S.C.; Savannah, Ga.; and New Orleans.

"The bronze-colored plates and glass-panel façade that make up the corona is a representation of traditional African architecture using modern materials and will visually define the museum," says Matt Wurster from Clark Construction Group, Bethseda, Md., one of the general contractors for the project.

The corona forms a perimeter zone around the museum's primary galleries, from which abundant daylight enters through the patterned openings in the cladding and skylights. To control the amount of sunlight and transparency allowed into the interior, the density of the pattern varies. The structure, which weighs 230 tons, hangs down from the top of the building by a series of steel outriggers.

The metal panels vary in porosity from 65 percent to 95 percent solid. "The varying porosity is an important element to provide solar screening to the inner glass enclosure," Davis says. "It varies based upon the visitor's viewpoints to the exterior of the building."

 

Smithsonian National Museum of African American History and Culture, NMAAHCBeautifully Bronze

A monumental component of the project's design, Zena Howard, AIA, LEED AP, civic + cultural co-market leader at Perkins+Will, explains that the color choice was discussed by all parties involved over the course of years. Bronze was ultimately selected, as the team said it would remain "an enduring and permanent color that would command respect for the building and the exhibits housed inside."

Finding the perfect hue of bronze was another challenge. Three custom shades-African Sunset, African Sunrise and African Rose, and one standard shade of Black Valspar Fluropon coating from Minneapolis-based Valspar Corp., were used on the 4-foot by 5-foot aluminum panels, which weigh around 200 pounds. "The color-matching period lasted for more than 18 months because we were looking for depth even more than just color since the panels were so intricate and unique," says Del Stephens, president and CEO of Dura Industries Inc., Portland, Ore.,  the project's metal panel applicators.

Custom cast by Seattle-based Morel Industries Inc., each panel was finished with five different coating layers, each a different color of the Fluropon coating, to achieve the desired bronze shade. The final color created was called "Artisan 3.5." Valspar's Fluropon coatings allowed the individual coatings to hold their color across every layer, since each new additional color builds off the last one to create the final shade. During the coating application process, extensive testing was done due to the sheer size of the panels, as well as the intricate design already cut into each piece. The team at Dura Industries applied the coating entirely by hand; with each color layer carefully inspected to make sure every part of the coating process was on track.

"What we ended up with gave us the look of real bronze, a luminous feeling that created a dynamic and beautiful façade," says Howard. Davis adds, "The idea was to express African American culture in a different way than stone could and provide a range of bronze color depending upon the time of day, weather and exposure of each façade seasonally."

 

Smithsonian National Museum of African American History and Culture, NMAAHCA Seed for Healing

Every museum project is different, especially history museums, notes Davis. "Having worked for 12 years with the Native American community on the Smithsonian's National Museum of the American Indian (NMAI) and the NMAI Cultural Resource Center, we learned a great deal that is different from what our history books taught us," he explains. "For the NMAAHC, it has been an even more immersive learning experience. When we actually opened, we had no idea what issues would be prevalent in the U.S. or in the world. Given all that has happened this past year with increasing racial tensions and bigotry, it could not have opened at a better time. We are all hoping that it can be a seed for healing."

 

Sustainable Features

Expected to achieve LEED Gold certification, the NMAAHC is the most sustainable national museum ever built. Some of its sustainable features include:

  • Climate-responsive form
  • Thermal zones in the building based on different spatial needs
  • Full commissioning of the building to measure and verify compliance
  • 30 percent energy reduction from established ASHRAE baselines
  • Energy performance complying with the Energy Independence and Security Act 2007
  • Construction waste management
  • Use of recycled and recyclable materials
  • Use of regional materials (500-mile radius)
  • Use of Forest Stewardship Council-certified wood and wood-based materials
  • Maximize daylighting and reduce energy costs
  • Daylight for 50 percent of the operational hours throughout the year
  • 75 percent daylight in all staff spaces
  • Stormwater management
  • Rainwater harvesting
  • Ground-source heat pumps
  • Water-efficient fixtures
  • Carbon dioxide monitoring

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Click on image below for larger view]

 Smithsonian NMAAHC Building Profile

 

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