Some tips for finding underground houses for sale include talking to a local Realtor about finding an underground home and checking classified ads or real estate websites for unique homes for sale. Moving to states such as Arizona and New Mexico makes it easier to find underground houses.
Arizona, California and New Mexico have many storm and bomb shelters that were converted into underground houses. Asking a Realtor to check listings of underground houses is a first step to finding such a property.
Diana and Ed Peden of MissileBases.com sell abandoned missile sites to people who want to convert them into underground houses and residences. Contractors who specialize in designing and building earth-sheltered houses can be a good lead to finding an underground house.