What Is a Geodesic Dome? What Are Space-Frame Structures?

Designing, Engineering, and Building With Geometry

Illustration of Geodesic Dome
Illustration of Geodesic Dome. Illustration by Encyclopaedia Britannica/Universal Images Group/Getty Images (cropped)

A geodesic dome is a spherical space-frame structure composed of a complex network of triangles. The linked triangles create a self-bracing framework that is structurally strong yet elegantly delicate. The geodesic dome could be called the manifestation of the phrase "less is more," as a minimum of building materials geometrically arranged ensures a design both strong and lightweight—especially when the framework is covered with modern siding materials like ETFE.

The design allows massive interior space, free from columns or other supports.

A space-frame is the three-dimensional (3D) structural framework that enables a geodesic dome to exist, as opposed to a typical building's two-dimensional (2D) frame of length and width. The "space" in this sense is not "outer space," although the resultant structures sometimes look like they come from the Age of Space Exploration.

The term geodesic is from Latin, meaning "earth dividing." A geodesic line is the shortest distance between any two points on a sphere.

Inventors of the Geodesic Dome:

Domes are a relatively recent invention in architecture.  Rome's Pantheon, rebuilt around 125 AD, is one of the oldest large domes. In order to support the weight of the heavy building materials in early domes, the walls beneath were made very thick and the top of the dome became thinner. In the case of the Pantheon in Rome, an open hole or oculus is at the dome's apex.

The the idea of combining triangles with the architectural arch was pioneered in 1919 by German engineer Dr. Walther Bauersfeld. By 1923, Bauersfeld had designed the world's first projection planetarium for the Zeiss Company in Jena, Germany. However, it was R. Buckminster Fuller (1895-1983) who conceived and popularized the concept of geodesic domes being used as homes.

Fuller's first patent for a geodesic dome was issued in 1954. In 1967 his design was shown to the world with "Biosphere" constructed for Expo '67 in Montreal, Canada. Fuller claimed that it would be possible to enclose mid-town Manhattan in New York City with a two-mile wide temperature-controlled dome like the one presented at the Montreal exposition. The dome, he said, would pay for itself within ten years...just from the savings of snow-removal costs.

On the 50th anniversary of receiving a patent for the geodesic dome, R. Buckminster Fuller was commemorated on a US postage stamp in 2004. An index of his patents can be found at the Buckminster Fuller Institute.

The triangle continues to be used as a means to strengthen architectural height, as evidenced in many skyscrapers, including One World Trade Center in New York City. Note the massive, elongated triangular sides on this and other tall buildings.

About Space-Frame Structures:

Dr. Mario Salvadori reminds us that "rectangles are not inherently stiff." So, none other than Alexander Graham Bell came up with the idea of triangulating large roof frames to cover large, barrier-free interior spaces. "Thus," write Salvadori, "the modern space frame sprang from the mind of an electrical engineer and gave rise to a whole family of roofs having the enormous advantage of modular construction, easy assemblage, economy, and visual impact."

In 1960, The Harvard Crimson described the geodesic dome as "a structure composed of a large number of five-sided figures." If you build your own geodesic dome model, you'll get an idea of how triangles are put together to form hexagons and pentagons. The geometry can be assembled to form all kinds of interior spaces, like architect I.M. Pei's Pyramid at The Louvre and the gridshell forms used for the tensile architecture of Frei Otto and Shigeru Ban.

Additional Definitions:

"Geodesic Dome: A structure consisting of a multiplicity of similar, light, straight-line elements (usually in tension) which form a grid in the shape of a dome."—Dictionary of Architecture and Construction, Cyril M. Harris, ed., McGraw- Hill, 1975, p. 227
"Space-Frame: A three-dimensional framework for enclosing spaces, in which all members are interconnected and act as a single entity, resisting loads applied in any direction."—Dictionary of Architecture, 3rd ed. Penguin, 1980, p. 304

Examples of Geodesic Domes:

Geodesic domes are efficient, inexpensive, and durable. Corrugated metal dome homes have been assembled in undeveloped parts of the world for only hundreds of dollars. Plastic and fiberglass domes are used for sensitive radar equipment in Arctic regions and for weather stations around the world. Geodesic domes are also used for emergency shelter and mobile military housing.

The best-known structure built in the manner of a geodesic dome may be Spaceship Earth, the AT&T Pavilion at EPCOT in Disney World, Florida. The EPCOT icon is an adaptation of Buckminster Fuller's geodesic dome. Other structures using this type of architecture include the Tacoma Dome in Washington State, Milwaukee's Mitchell Park Conservatory in Wisconsin, the St. Louis Climatron, the Biosphere desert project in Arizona, the Greater Des Moines Botanical Garden Conservatory in Iowa, and many projects created with ETFE including the Eden Project in Britain.

Sources: Why Buildings Stand Up by Mario Salvadori, Norton 1980, McGraw-Hill 1982, p. 162;  Fuller, Nervi Candela to Deliver 1961-62 Norton Lecture Series, The Harvard Crimson, November 15, 1960 [accessed May 28, 2016]; History of Carl Zeiss Planetariums, Zeiss [accessed April 28, 2017]