On this daf, we find some discussion of building fences.
A certain person purchased the top floor apartment in a large building and naturally figured that this included the rooftop that was over his apartment. After all, what did the other tenants of the building care if he makes use of the roof? Although the roof had a small ma’akah, no one ever used it, so as long as he was careful not to disturb the solar water heaters, he figured that he could do what he wanted. After many years, he already had a big family and decided to fence in the area above his house and build a staircase from his porch to the roof to provide easy access.
This step infuriated one of his neighbors, who was hotheaded to begin with. After the neighbor warned this man to take down the fence and was rebuffed, he resolved not to allow him to get away with what he saw as theft from all the neighbors. After all, theoretically, it was possible for the entire building to receive permission to add two more stories to the building, which would be split between all sixteen apartment owners. But if they allowed the top floor neighbor to attain a chazakah, they would lose all possibility of profiting from the roof.
The next time that the family that lived on the top floor went out, their neighbor below climbed the ladder to the roof and cut down the entire fence that had enclosed the roof. When the neighbor upstairs returned home, he was shocked at this blatant vandalism, but the vandal paid the entire cost of the damage on condition that they go to a posek for adjudication of their dispute.
When this question was presented to Rav Yisroel Grossman, he ruled, “I am sorry, but it is eminently clear that you overstepped here. It is clear from Shulchan Aruch that one who did not specify that he purchased the roof rights in writing when procuring his apartment may not build on it without his neighbor’s explicit permission” (Shu”t Mishkenos Yisroel #3).