No idea. Just covered the additional costs (dormers, front gable)? Many builders might not even realize that the BP causes additional costs. Not everyone has or sees a problem with the development plan. If you build with a basement, it looks different again.
Well, it's hardly worth discussing ... hopefully the architect will deal with that at the building authority ;)
I was simply thinking of a kind of exemption as is possible with the Energy Saving Ordinance §25. Why shouldn't something like that make sense with a BP as well? For example, the plinth, I understand it to mean that the entire house must stand on a plinth that is at least 0.5m high. What does that achieve? Or is it just a visual separation of the facade from the ground?