Grade

1. The ground elevation at the building site. The portion of a building structure which is over the grade, is termed above grade. The foundation or any subterranean portions of a building is termed below grade.
   
2. Method of classifying building materials. Grades of lumber are particularly important when choosing an appropriate building material.
   
3. The rate of rise or fall of a roadway. The grade of a highway is normally expressed as feet per 100 ft. or as meters per kilometer. Ascending grade is expressed in positive numbers while descending grade is expressed in negative numbers.