The Delightful Dome is a “monolithic structure”, consisting of an outer shell of dense insulating foam and an inner shell of concrete). The heated adobe/concrete floor provides thermal mass that moderates temperatures inside the dome. The structure is earthquake-proof, tornado-proof, and hurricane-proof.
Find out more about monolithic domes in the videos below, or at www.monolithic.org.
Pretty cool!
Radon: A radon mitigation system is installed in the dome. It consists of a fan that exhausts air from the subfloor foundation (audible on north side of dome). A radon test in 2017 showed air levels in the dome of 0.28 picocuries/liter, well below the EPA threshold of 4.0 pc/l.