Does the sidewalk belong to the common property or the municipality? The declaration of division regulates the individual parcels among each other - the whole area, that is the entire property, is subject to the general neighborhood law/building law of the state. That would be my understanding from reading the bits of the contributions.
And if palisade fences with a height of 100 cm _without indication of terrain slope or reference height_ are allowed, then they may be 100 cm high, even if they are higher or lower from one side or the other.
Basically, it is difficult to address guidelines and legal systems when they are only partially extracted and the entirety is missing for the readers. Often individual rules rely on previous ones, so gaps in the citation can have fatal consequences. Sometimes it only takes one word, which is replaced by TE with ellipses.
Regards