What is meant by "below grade" in construction?

In construction, the term "below grade" refers specifically to the portions of a building that are located below the ground level. This typically includes basements, underground parking garages, and any structural elements that extend below the natural surface level. Understanding this concept is essential for construction practices, as it impacts design, drainage, waterproofing, and other critical decisions regarding structural integrity and utility access.

The distinction is important because "below grade" areas often require different considerations compared to above-ground structures, particularly concerning moisture control, insulation, and ventilation. For instance, building codes and regulations often have specific requirements for below-grade construction to protect against water ingress and to ensure the safety and habitability of the spaces located there.