What is Basement?

Definition of Basement in Construction
Although a very common term, the word basement is sometimes confused in commercial construction. In residential construction, basement is the space under the first floor that could be deep enough for occupancy or in other cases only a crawl space. The term must be carefully interpreted, due to its common inferences. In the commercial industry, the basement level is also the foundation level, the level below grade, etc. Care must be taken to properly understand and communicate the use of the term basement on each specific project. If a commercial structure has several levels below grade, what is considered the basement? Is it all the levels, just the lower level, etc. This is why the term must be clearly identified to prevent confusion.