I think yes it is less 3d-printed if it is assembled out of multiple pieces.
How small would the pieces have to be before you say it's not a 3d-printed building? Is a building made out of 3d-printed bricks a 3d-printed building or are the bricks 3d-printed but the building not?
The limit as piece size tends to zero is that 3d-printed-ness tends to 0.
I wonder what happens if we go in the other direction.
Instead of printing a single building as one piece, what if we print a whole city block as a single piece. Are those buildings 3d-printed then, or are they just part of a 3d-printed bigger whole? Asking seriously btw.