Final answer:
The minimum net clear opening of grade floor openings is determined by building codes and regulations. For commercial buildings, the International Building Code (IBC) specifies a minimum net clear opening of 20 square feet. Consult specific building codes for exact requirements.
Step-by-step explanation:
The minimum net clear opening of grade floor openings is determined by building codes and regulations. These codes vary depending on the jurisdiction, but as an example, let's consider the International Building Code (IBC) which is widely adopted.
According to the IBC, grade floor openings in a commercial building shall have a minimum net clear opening of 20 square feet. However, this value may change depending on the occupancy type and the number of occupants the building is designed for.
It's important to consult the specific building codes and regulations in your area to determine the exact requirements for grade floor openings.