Geodesic domes are polyhedrons (geometric bodies with flat faces) whose triangular “faces” generate hexagons or pentagons and whose vertices coincide or touch the surface of an imaginary sphere that circumscribes it. The are structures that are detached from the geodesic domes are detached from the “spatial grids” that make up various “structural systems”. Spatial meshes are made up of a large number of small bars, taking into account the scope of the entire structure.
The bars are connected to each other by their vertices, creating triangles, which form pentagons and hexagons, thus forming a “three-dimensional network”. This three-dimensional network works by the concerted action of different pieces that are assembled together directing forces and transmitting loads.
Each triangular face of the Dome is in turn subdivided into smaller triangles, and depending on the number of times this subdivision is made, we achieve the different frequencies of the geodesic domes.
All of this makes them strong building structures despite their fragile appearance, and one of the best ways to build a room entirely with glass. We could have an orchard or garden inside a room built as a geodesic dome. They can also be the base of the structure of a construction of any other material.
It is considered that it was Richard Buckminster Fuller who invented geodesic domes, since he is the one who holds his patent in 1954. Fuller developed them in the 1940s, creating one of the best-known geodesic domes in 1967 at the Montreal International Exposition, 76 m in diameter and 41.5 m high.
Despite this, there are earlier examples of geodesic domes, such as in the Imperial Palace of China (1885) or in the planetarium of the Carl Zeiss workshops (1922).
In the Imperial Palace of China (Forbidden City, Beijing), belonging to the Ming and Qing dynasties, you can see a sphere with a geodesic subdivision of an icosahedron. It is a sphere under the claw of a guardian lion in the Nurturing Heart Gate, similar to another in the Summer Palace in China (near Beijing), dating from approximately 1885.
As for the planetarium of the Carl Zeiss workshops, it is a frequency 16 geodesic dome created by Walter Bauerfeld, which came to be called “the wonder of Jena”. From this, many others were created, until the idea was developed by Fuller.
Different types of geodesic domes
Geodesic domes and geodesic domes can be classified according to different aspects.
1. Frequencies of the domes:
Geodesic domes are generated from the 5 Platonic Solids which are the following Geometric shapes:
As the Frequency rises, more and more ends and more connectors are necessary, but each time we are achieving more point of contact with the Sphere, that is why the higher the frequency, the more round the geodesic becomes.
For example, a 2 V Dome has 65 bars; one 3 V carries 120 or 165 bars, and one 4 V 250 bars.
Here you can consult a dome frequency calculator.
2. Anchors
The most common are metal anchors with wooden bars. There are approximately 8 types of metallic connectors, hexagonal, pentagonal and quadruple, each one of them with angular variations to conform the geodesic geometry. In a construction, they are invisible from the outside covered by the cover. Inside they are covered with cladding or with a wooden finish. The beams are held together by a metal anchor with various angles. You can see in the detailed photos the models of 2.5 mm iron metal connectors.
On the other hand, you can find different, less common connectors:
How to build a geodesic dome
In this interesting home video tutorial (which has 9 parts), a builder explains how the geodesic system works and shows how to build a dome with recycled material: pallets, mud, car tires and straw, among other materials.
And you, will you dare to build?