Earthships can be fully above ground, wrapped with straw bales or 4″ rigid insulation (depends on climate) and finished with conventional facing. If the climate is temperate then the configuration of the layout of the rooms in an earthship can be altered.
Every state, county, city, neighborhood association, etc. has rulse and regulations. Most are ‘old’ and inadequate and no longer apply and must evolve with society. This results in a ‘re-education’ process to the officials, usually at the county level. The more temperate a climate the easier it is to apply earthship biotecture to existing structures and the easier it is to make earthship biotecture look more conventional. Earthship look the way they look because that is the best performing structure for humans on the planet. Best meaning providing the essentials and minimal impact on the planet and ease of use for a 21st century society. Existing apartment buildings, hotels, home with yards, high rise buildings, munipal sewage treatment plants, parks, etc. can all be ‘retrofitted’ with earthship biotecture to provide the essentials and minimal impact on the planet and ease of use for a 21st century society, we’re used to amenities and we are entitled to have them all – but sustainably, which is actually pretty easy, its physics and biology to make structures (architecture) which equals biotecture, resulting in earthships, but can also result in retrotfitting existing structures and systems.