Eaves height and roof shape in new construction planning

You should submit the plan completely, including the graphical part. Otherwise, there is always the risk that things will be taken out of context.

I can see the explanation of the planning part, but not the plan. The restrictions such as full floors and floor area ratio are mentioned there.

And does the eave height always apply, regardless of whether you build one or two stories?

Yes, unless the development plan explicitly sets something different, which it does not in your case.

In a neighboring development area

... it is not worth looking for comparisons, as a different development plan applies there.

So if the 3.50 m eave height were fixed

Yes, it is. But I didn’t know that there are plots with slopes in Lower Saxony . A creative architect or some active members here in the forum could maybe conjure up something townhouse-like with a basement for you. However, for that you need a site plan of the plot with precisely measured plot boundaries, building boundaries and above all heights, including planned street heights.

I agree with that about the roof shape

Me too.

but I’m not sure

Me neither. Ask the municipality how they see it.

if it even fits together geometrically

It doesn’t have to. These are all maximum specifications.

Because how am I supposed to get to 8.50 m ridge height with 3.50 m eave height and max. 35° roof pitch

With a shed roof the height is easily achieved.

*slaps forehead*
That certainly makes everything make sense.
It is not two full stories that are required, but only the maximum ridge height.
And with a 0.4 floor area ratio, the outbuildings are included in the calculation, so a 0.5 floor space index and the planning specification also make sense.

Okay, I hadn’t considered the shed roof either, but even with that the eaves height is very low. If the full floors had been limited right from the start, then even the inexperienced property buyer would understand what is actually intended/allowed.

Say - simply in text format instead of a link - so "Posemuckel Nr. 815 in den Wiesen" as the development plan is called, then we can Google it.

By the way, laypeople like to lump (both pictorial and textual) information together that applies to different building fields of the same development plan.

Exactly the question I asked myself about the ridge and eave height, whether they actually fit geometrically at all, or whether that is a contradiction in itself (2 full floors, 3.50 m eave height, 8.5 m ridge height, shed, hip and gable roof with roof pitch 28-35°).

You might be assuming from the misinterpretation that with full floors only vertical wall floors are meant – but it can also mean pitched roof floors with more than 2/3 or 3/4 of the "reference area" of the floor below.

A tent roof is a ridge-less hip roof, as it typically arises over a square floor plan. But even a joking ridge of half a meter "length" would be possible if the building authority insists on hallucinating a difference there: on a square floor plan of 10 x 10 m and transversely a roof pitch of 28°, a ridge of 80 cm length would result with a longitudinal roof pitch of 30°: you don’t see the 2° pitch difference and the building authority is satisfied.

From my point of view, it's usually not a loss to be unable to build a "city villa" – what is the motivation behind this desire in your case?