Hello Chris,
Kniestock 80cm
Dachneigung 38°
Wandstärke 36cm
1. 80 cm knee wall outside is approx. 100 cm inside
2. 80 cm knee wall outside is approx. 65 cm inside
Excerpt from development plan
The knee wall height (knee wall height)
of the attic must not exceed 80 cm. The knee wall height is defined as the distance between the top edge of the attic floor and the cutting line of the outer surface of the wall with the lower edge of the roof covering.
It "could" well be that both calculate correctly but have different approaches. One might be measuring from the raw floor to the intersection of the roof covering, the other perhaps from the finished floor (FF) to the clad roof slope = finished measurement.
The city of Nauen refers to the development plan..
That is their right; with the development plan, the city can, among other things, specify its own heights.
Would an appointment at the building authority on site be a possibility?
Of course you can do that; the city of Nauen surely offers building consultation for builders as well.
On the other hand – why should you do that, apart from a first introduction to the topic of house construction in Nauen? The temporary construction partner you choose owes you compliance with the development plan. If an architectural office is commissioned beforehand, it is among other things the planner's duty to comply with the specifications of the development plan.
Rhineland regards