Like the word penthouse, do the apartments built -60 centimeters below the ground floor have a particular name?
One such term is garden-level apartment.
A garden-level apartment is considered to be generally situated between a basement and first floor, so that people standing up inside it would find their heads at or around street level.
You are probably looking for
a part of a building consisting of rooms that are partly or completely below the level of the ground:
- Our kitchenware department is in the basement.
- a basement flat