Underground homes is a bold option for those who are interested in their own construction of a house from scratch and have as main target cast reduction and maintenance.
In winter, when the temperature outsides is below zero, the land will remain warm. In these condition, the temperature insides a house build partially below ground surface will remain elevated even in the coldest days.
On the other hand, in summer, the convenience of such a home is high due to property that has ground conductor.
Beside advantages, there are disadvantages of course as well: if the basement is entrance ramp, there is a need for water drainage rain water. Water gathered will be removed from drains or failing. A further disadvantage is earthquake risk. Being in an underground house will be difficult to escape.