The Class 2 version of the 6 frequency octahedral dome
Standard orientation gives four squares on the bottom and one on top. As shown on this 2 x 4 tall version with more height than the hemisphere dome. To make bottom squares tall enough to fit a standard size door, diameter is 36 ft. and height is 21 ft, 8 inches. The hemisphere dome, shorter version and the Edge Zenith version can be made.
Tall version:
The Edge Zenith version has 2 squares toward the top:
