An igloo-shaped magnesium structure, supported on a sintered regolith, covered by sandbags of regolith shielding, and made using rapid manufacturing technologies is proposed as a potential design of a lunar structure. Lunar thermal environment has been modeled and a thermal analysis is carried out to study the effect of the regolith shielding as well as the sensitivity of such designs to measurement uncertainties of regolith and sintered thermal properties. It is shown that a three-meter thick regolith shielding can insulate the structure regardless of its location on the Moon. Also, a seismic event of body wave magnitude 7 has been developed based on best available data and applied to our typical structure. During the Apollo missions seismic events with estimated magnitudes of 5.5 were observed. Therefore, we begin to consider lunar seismic effects to assess the vulnerability of designs that ignore seismicity. The results indicate that the risk associated with these events is low in part because such structures are designed with a relatively high factor of safety. This paper provides an extensive and specific technical discussion of thermal analysis and seismology as applicable to structural design.