NCAR: Modernism on the Mesa


Leonard Segel


KEPHART- Denver; Docomomo US/Colorado


Regional Spotlight, Colorado
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Rocky Mountain Modern Part Three
NCAR: Modernism on the Mesa

The design of the National Center for Atmospheric Research (NCAR) is a masterpiece of the Modern Movement in architecture.  It is the foundational, break-out design by I.M. Pei that kicked off his extraordinary career. 

NCAR came about as a priority of President Eisenhower. He wanted a science institute that was dedicated to better predicting the weather, primarily for strategic reasons. It was during the Cold War that his idea was to disperse the important science research and military centers from out of harm’s way in Washington D.C. into the middle section of the U.S. Colorado was ideal and landed NORAD and the Air Force Academy in Colorado Springs, and NOAA, NIST and NCAR in Boulder.

The radical design of NCAR was welcome in Boulder. The post WWII boom brought a remarkable number of Modern Movement buildings to the town. The National Institute of Standards (NIST) is a modernist gem by architects William Pereira and Charles Luckman. The University of Colorado spread the word about modernism through its college of architecture which brought lectures in the 1950’s and 60’s by Frank Lloyd Wright, Bruce Goff and Buckminster Fuller, among others. The citizenry of Boulder was highly attuned to the progressive ideas of the modern design movement.

The founding director of NCAR, Walter Orr Roberts, was a scientific innovator and was connected to the East Coast university establishment, having graduated from Harvard.  He envisioned a Colorado version of Caltech located on a spectacular mesa-top site above Boulder. It was to be a sort of Acropolis of science (Walter Netsch had a similar idea for his Air Force Academy Campus in Colorado Springs). In his nationwide search for an appropriate architect, he selected I.M. Pei, a Harvard graduate. Other architects considered included Louis Kahn, Minoru Yamasaki, Eero Saarinen, Richard Neutra and Alvar Aalto. 

Pei was already familiar with Colorado, having done large-scale, commercial design work in Denver while he was the “in-house” architect for the Zeckendorf development company. NCAR was among the first major commissions of his newly formed private architecture firm. Pei was given the building program of spaces and the location which had already been determined by Roberts.

You just cannot compete with the scale of the Rockies. So we tried to make a building that was without the conventional scale you get from recognizable floor heights – as in those monolithic structures that still survive from the cliff-dwelling Indians.

I.M. Pei

Pei’s preparations included an examination of indigenous architecture in the southwest. He drove from Albuquerque to Boulder, looking at Native American settlements. It was the ancient Ancestral Puebloan cliff dwellings at Mesa Verde that proved to be one of his most highly influential design inspirations. Contemporary influences visible in the executed design come from Walter Gropius and Marcel Breuer (two of Pei’s favorite instructors at Harvard), Le Corbusier, who had recently completed the Carpenter Center at Harvard, and the gifted architect Paul Rudolph, another Harvard grad.

From 1962 to 1964 Pei dedicated a significant portion of the time of his firm to designing NCAR. Roberts pushed him to develop several design options, continuously demanding higher levels of quality.  The concept evolved from a monolithic building to a “village.” Remarkably the building is a geometric composition of just two materials, concrete and glass, that creates space and sculpts light. It has a corduroy texture that softens the material. The sculptural forms are determined by the functions of the spaces within. Shading and window orientation are a big piece of the magic of this project. Many of the windows are recessed or have hooded overhangs to provide protection from the strong sunlight. 

The NCAR building, designed with isolated towers, reflects Roberts’ vision for the institution as a collection of (400) researchers pursuing individual projects. The guiding metaphor is the ‘village' . . . a self-directed community of scientific peers. NCAR is a place that brings together meteorological observational data from across the globe to be analyzed, interpreted, and built into models by the NCAR staff, visiting scientists, and distant collaborators.  It is a community linked by networks of computers.

The ‘village’ is comprised of three, five-story towers arranged around a terrace and interconnected by a plaza at ground level, a two-story core building, and a basement linking it all underneath. The core building houses communal spaces, including the lobby, a small science museum, meeting rooms, a lecture hall, cafeteria, and library. The towers have laboratories and offices. The machine shops and heavy floor-load laboratories, including computers, are in a two-level basement. On the top floors of the towers Pei designed “crows’ nests,” with full glass fronts and a tiny perch for inspiring views. These give the scientists a respite from the intense demands of research.

With a nod to the Alhambra Palace, which Pei had mentioned to Roberts as a perfect example of a compact, contemplative space, the design included a fountain, anchoring a central courtyard. It leads to a tree-lined plaza for private conversations or larger public gatherings. Yet another Harvard graduate, Dan Kiley, was involved with the project as landscape architect. Kiley was known for his geometric and modernist approach to landscape design which are evident in these plazas. He linked NCAR to the site with pathways through meadows to the parking lots and through a pine forest to hiking trails leading to the Flatirons.

In April 1964 the construction on the facility began.  The building was completed in 1966 and dedicated in 1967. It has been considered a success in the scientific and architectural communities, even winning the coveted “25-year Award” from the American Institute of Architects. It remains the spiritual ‘heart’ of the NCAR network, with several other related labs in Boulder and Wyoming.

Standing alone on top of the mesa, NCAR appears like an apparition above the town of Boulder below. The design is timelessly enigmatic; it looks both ancient and futuristic. Architecturally it is successful on multiple levels. The design is expressive of its spectacular natural setting, is inspired by the science that takes place within, and literally elevates the users to a higher plane of awareness with its unusually inventive building language. This project established I.M. Pei as an impressive master within the Modern Movement.


Leslie, Stuart. "A Different Kind of Beauty: Scientific and Architectural Style in I.M. Pei's Mesa Laboratory and Louis Kahn's Salk Institute." Historical Studies in the Natural Sciences, Vol. 38, Issue 2, 2008.

Leslie, Stuart. “Laboratory architecture: Building for an Uncertain Future.” Physics Today, Issue 63, 2010. 

Michael Paglia, Leonard Segel and Diane Wray. Historic Context and Survey of Modern Architecture in Boulder, Colorado, 1947 – 1977. June 1, 2010.

Paul Rudolph Heritage Foundation: Art and Architecture Building for Yale University (1958 to 1963).

About the Author

Leonard Segel is a 30-year resident of Boulder.  He is an architect at KEPHART in Denver, has taught architectural design at the University of Colorado Boulder and has a personal connection to NCAR.  Tician Papachristou was the architectural advisor to Walter Orr Roberts during the entire period of the development of the NCAR Mesa Lab.  Years later, Len worked for Papachristou in the successor firm of Marcel Breuer in New York City and heard stories about the NCAR project.  Len is a founding member of the Docomomo US/Colorado chapter and serves on the Board of Directors. A year ago he gave a lecture at NCAR about this Pei project and its relationship to the strong heritage of Modernism in Boulder for the 2019 National Trust for Historic Preservation conference.   

Rocky Mountain Modern is part of the Docomomo US Regional Spotlight on Modernism Series, which was launched to help you explore modern places throughout the country without leaving your home. Previous spotlights include Chicago, MississippiMidland, MichiganHouston and Las Vegas. Have a region you'd like to see highlighted? Submit an article.

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Rocky Mountain Modern Part Four
The Simple Buildings: The Career of William Robb in Fort Collins