Unless you’ve been living in a cave for the past half century, you have probably encountered a geodesic dome at one time or another. They can be found on playgrounds, at amusement parks, and in museums; and any number of homes and public buildings are constructed using some variation of this structure. Depending on your tastes and disposition, you may think geodesic domes look cool, endearingly retro, or woefully unfashionable. But you may not know the story (and the logic) behind this sometimes-controversial design.

Bucky-ing Trends

R. Buckminster Fuller was one of the most prolific thinkers and inventors of the 20th century. He wrote numerous books, received dozens of patents, and worked tirelessly for decades to solve some of the world’s most vexing problems using the tools of engineering and common sense. For all his innovations, Fuller was a very practical man, and like most engineers he saw a great beauty in elegantly logical solutions—even if they defied tradition, aesthetics, or conventional wisdom. So when a housing crisis arose in the years following World War II, he set out to find the simplest and most effective solution, no matter how unusual it may be.

Fuller loved geometry, and he was particularly impressed by the triangle, the most stable geometrical shape. Many of his building designs involve triangles, because they provide the greatest structural integrity. He also knew that the sphere was the most efficient three-dimensional shape, enclosing the largest possible volume with the smallest surface area—meaning a dome (a partial sphere) should be a logical shape for a building. But dome-shaped buildings are notoriously awkward to construct. Fuller’s innovation was a way to create a sphere (or partial sphere) out of triangles, providing the best of both worlds. He called this shape a geodesic dome, because the pattern of triangles forms an interlocking web of geodesics. A geodesic is the shortest path between two points. This is, of course, a line in two-dimensional geometry, but on the surface of a sphere, the shortest distance between two points is an arc defined by a great circle—a circle with the same diameter as the sphere (like the equator).

The Miracle Building

If all that geometry is too much to wrap your brain around, consider the main advantage Fuller cited in his 1951 patent application for the geodesic dome: this shape, because it is self-reinforcing, requires far less building material than any other design. Conventional buildings, according to Fuller, weigh about 50 pounds (22.7kg) for each square foot (0.09 sq meter) of floor space. A geodesic dome can weigh less than 1 pound (0.5kg) for each square foot of floor space. (One of Fuller’s original geodesic domes was a metal framework lined with a sheet of heavy, flexible plastic.) The upshot of this is that you can create buildings quite inexpensively, and with a minimum of equipment and labor. Geodesic domes are also stronger than conventional buildings, highly resistant to earthquakes and wind, and more energy-efficient too. What’s not to like?

Well, that’s a circular question. The main problem with a dome-shaped building is that although it encloses a large volume of space, a lot of that space is not easily usable by humans. The slope of the walls means the floor space is effectively limited (more so, the taller you are), and most furniture, having been designed for flat walls and corners, doesn’t fit well. There’s also the fact that you need a fairly large lot for a dome of any reasonable height; in urban areas, such real estate may be hard to come by. Multiple levels within a dome are possible (thus making better use of vertical space) but those introduce additional engineering challenges—and expense. And banks are generally hesitant to provide home loans for dome builders; they’re seen as a risky investment, because there’s no way to gauge their resale value.

All these issues in no way diminish my enthusiasm for Fuller’s design, because I feel, as he did, that logic and elegance count for a lot. Plus—let’s not beat around the sphere—I think geodesic domes look impressive, and I imagine it would be interesting to live in a space without right angles. If fortune ever smiles upon me broadly enough that I can afford to build my own home, you can be certain a dome will find its way into the design somewhere.

Note: This is an updated version of an article that originally appeared on Interesting Thing of the Day on October 22, 2003, and again in a slightly revised form on January 5, 2005.