Click on your choice for a detailed explanation - Then look below.
The Theory Platonic And Archimedian Solids Face Variations
Projection Variations Truncations Variations Why Choose Geodesic?

A “geodesic” is a line joining two points on the surface of the earth. A geodesic structure is one that follows the surface geometry of a sphere. But there are many kinds of dome structures that do this. What defines a dome as a geodesic structure? Geodesics Unlimited follows the lead of the Surrey University Space Structures Research Centre, which, in our view, is the world’s leading authority on the configuration of space frame structures, of which the geodesic dome is one. So here below are the main varieties of domes, their names, and their defining features.



Schwedler Dome


This has ribs extending down from the crown of the dome, rings extending horizontally around the dome, and diagonals extending from intersections between ribs and rings on one horizontal ring to those on the next .



Ribbed Dome


This has ribs extending down from the crown of the dome and rings extending horizontally around the dome.



Lamella Dome


This has diagonals extending from the crown down towards the equator of the dome, in both clockwise and anti-clockwise directions, and may or may not have horizontal rings, but has no meridional ribs.



Diamatic Dome


This has what may be described as pie-shaped sectors repeated radially around the crown. Here, the apex of each sector has a width of zero and, at its base, a sector is 360 degrees divided by the number of sectors .



Great Circle Dome


This is a dome not defined by the Space Structures Research Centre. We call it the Great Circle Dome as all of its elements follow more or less great circular paths over the surface of the dome.



Geodesic Dome


This dome is rather different in its origins. It is derived from one of the platonic or Archimedean solids, or from a prism or anti-prism - see Platonic and Archimedean Solids, and below.





Take for example the Icosahedron, which is a platonic solid with 20 regular triangular faces.





We take any face of this solid and subdivide it in any way we choose, for example as in the drawing on the left.





We then take this pattern, and project each intersection in the pattern outwards onto the surface of the sphere on which all the vertices of the original icosahedron sit.





We then replicate this around the whole of the icosahedron, as left. We also have the options of using a different base solid, a different projection, a different face pattern, and a different portion of the sphere. These possibilities are explored in the following pages