Roof structure on conservatory construction - legal question

If your neighbor puts a fence or wall on the boundary, you cannot look into his house or onto the terrace from the conservatory. If you have a terrace on the conservatory, you can easily look over it and in extreme cases even spit on his grill. That's definitely a difference.

By attaching a roof terrace to the conservatory structure, the conservatory loses its character and thereby becomes an extension.

Would you recommend that we first obtain the written consent of both neighbors (left and right) for the building application and attach these letters to the application?

This reasoning is as vague as the terms terrace, conservatory, and extension themselves. Unlike a full storey or the floor area ratio, the law does not define these terms, because a building part that deviates only slightly from the definition should no longer be legally classified in this category. Therefore, the building authority has discretionary power here. If you omitted the panes of the conservatory, you would no longer have a roof terrace, but an altan or, if the supports are also removed, a balcony. According to the development plan, these are not allowed to exceed the building boundary (I assume). However, your roof terrace would have the same effect from the neighbors’ and urban planning perspective. The approval procedure does not mean your request is not approvable. It just does not fit the exemption from approval, since it must be examined whether the construction still fits within the urban planning design or not.

If the distance areas are observed, the rear building boundary should not have a neighbor-protective significance and exceeding it should not violate the rights of the neighbors, so involvement would not be necessary. However, if obtaining the signatures is unproblematic, that could be helpful.