Calculate the projected area of ??a building?

There is a provision in the calculation standard for commercial housing construction area:

“The bay window of a house shall have the window sill and table level with the ground of the house (floor-to-ceiling), shall have the same functions as a house, and shall have a clear height of Above 2.10m, the area is calculated based on the horizontal projection between the outer edge of the exterior wall and the bay window enclosure."

This corresponds to the owner's requirement of "floating boards that do not float out from the floor surface." , the window sill plate does not count the horizontal projected area" question.

I don’t know if that’s what it means.