This is my dome homepage. It contains a few speculative drawings of residential-type domes and some verbage on designing and building them.

The shell of the dome pictured at this site is a 3-frequency geodesic ellipsoid (or prolate) with a long-to-short axis ratio of 1.7 to 1. Shells with different ratios can be calculated once the right formulas are entered into a spread sheet, but there are some big differences in going from a simple spherical geodesic to an ellipsoid. An ellipsoid generates seventeen distinct chord factors in place of 4, and twelve triangular facet patterns (not counting mirror patterns) in place of two. Dihedral angles are also unique to the new chords and facets.

Finding the chord factors, dihedral angles, etc. for ellipsoid geodesic domes was a pretty painful experience, but once I had a spread-sheet set up the figures were fairly easy to manipulate. I can generate complete numbers for any ratio of ellipsoid but only if (like the ones shown) it's based on what's commonly refered to as a geodesic 3v alternate breakdown. If your're interested in finding out the figures for your own building project or model and don't want to re-invent the wheel yourself, please let me know at or (I am also working on complete construction plans for the shell shown and hope to make them available on some reasonable basis in the future.)

Now a word about the design shown in the drawings. First, I can't entirely explain why geodesic domes appeal to me, but if your curiosity about domes brought you to this site, then maybe they appeal to you in a similarly serendipitous way. Several years ago in NSW, Australia I built a 38 ft sphereical dome, but just didn't get it out of my system. For one thing, I made so many obvious mistakes that I've been anxious ever since to start a new project, and that's where these plans come in.

I prefer the prolate shape of the shell simply because it soars. I know (as more than one person has pointed out to me) you can get the same height with a spherical half-shell on top of a cylindrical wall, but that makes sense only if aestetics mean absolutely nothing. Here unity of form manifests itself, and the height allows three stories. (The floor diameter is about 38 ft., the height about 39 ft.) The stacked look of the rooms with over-looking windows was inspired by pictures of the the Anasazi dwellings built into recessed cliffs in the Southwest. I think I just like the way the shell provides an intermediate space between conventional well-defined rooms and the outdoors.

Please feel free to comment on any of my designs. I'm interested in all aspectes of dome building. Thanks for visiting.

Bill Coyle

Exterior Drawings

Floor Plans


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Domes Bill Coyle 1998, 1999