What does “gross floor area” measure in building terms?

Gross floor area is defined as the total area of all floors within a building, which includes not only the occupied spaces but also the structural elements such as walls and columns. This measure provides a comprehensive overview of the building's size and is critical for various calculations involving building codes, zoning regulations, and property assessments.

Understanding gross floor area is essential in commercial building inspections as it affects compliance with building codes and regulations related to fire safety, occupancy, and functionality. It encompasses everything within the building's external walls, which can significantly impact design, layout decisions, and operational purposes.

In contrast, the options related to land occupancy, exterior structure only, or usable spaces only provide a more limited view. For instance, measuring only the land area would not reflect the building's internal layout, while focusing solely on usable spaces excludes important areas necessary for structural integrity and access. Therefore, choice B accurately captures the broader and more practical understanding of gross floor area within the context of building measurements.