Tricks in projectile calculation

It always depends on the federal state (and for us probably also somewhat on the building authority/caseworker) and is specified in the state building codes. In Lower Saxony, it really only concerns the pure 2/3. For example, we have a kind of "cantilever" in the living room, above which there is no living space, and the gable roof basically goes all the way down. With that, we were able to achieve a knee wall in the upper floor of about 1.6 meters. Right next door, a house is being built with a roof terrace above the living room – here the builders were really able to achieve a full ceiling height also in the upper floor (I assume this is a recessed floor).

For Baden-Württemberg, the following applies:

(6) Full storeys are storeys that protrude more than 1.4 m above the average measured ground surface and, measured from the top edge of the floor to the top edge of the floor of the ceiling above or to the top edge of the roof covering of the roof above, are at least 2.3 m high. The average measured ground surface is derived from the arithmetic mean of the elevation of the ground surface at the building corners. The following are not full storeys: 1. storeys that are exclusively used for housing building services equipment and heating systems, 2. top storeys where the height of 2.3 m exists over less than three quarters of the floor area of the storey below. Voids between the top ceiling and the roof, whose clear height is less than that required for habitable rooms according to § 34 para. 1, as well as open galleries up to a floor area of 20 m², are disregarded.

But unfortunately, I still do not fully understand it.

: Thanks for the great answer, that really helps me understand a lot better. The development plan does not mention setback floors, but I have simply scheduled an appointment with the mayor next week to clarify exactly what, how, and where is possible

: I also find it really complicated and am glad I'm not alone with this