The images below are from a4v, 51-foot (15 meter) geodesic dome construction, with a 7/12 profile *(more than a hemisphere) in Northen Vermont. Contrary to popular belief, even a dome with no basement requires a sizable concrete foundation.
One of the reasons for this is that the lift factor caused by winds is not to be underestimated. Also, this home will be built as a double shell (a dome inside a dome).
This is a video of the foundation interior being covered with insulation boards before concrete is poured over them.