A cellar is a space inside a building that is below its curb level or at least half its height. On the other hand, a basement is a story of a building with more than 50 % above the curb level and the rest underneath. You can use a curb level or a base plane for the measurements.

The main difference between a split-level and a basement is the very fact that a split-level has multiple floors and a basement is one continuous level. Split-level homes usually have a main level, then part of the home is lower than the main level; this is known as a lower level.

The main difference is, standard foundation walls are built partially underground and therefore don’t create livable space below the first level. By contrast, basement foundation walls are fully submerged to make space for an underground floor. Basement foundations take longer to build than standard foundations.