and the owner of the courtyard can protest its construction. If it protrudes less than a handbreadth, the owner of the house has no means to establish an acquired privilege for its use, and the owner of the courtyard cannot protest its construction.

GEMARA: Rabbi Asi says that Rabbi Mani says, and some say that Rabbi Ya’akov says that Rabbi Mani says: If one established an acquired privilege with regard to a projection of a handbreadth, he has established an acquired privilege with regard to four handbreadths. The Gemara asks: What is he saying? Abaye said that this is what he is saying: If one established an acquired privilege with regard to a projection that measures one handbreadth wide by four handbreadths long, he has established an acquired privilege with regard to extending the projection to a width of four handbreadths.

The mishna teaches that if the projection protrudes less than a handbreadth the owner of the house has no means to establish an acquired privilege for its use, and the owner of the courtyard cannot protest. Rav Huna says: They taught only that the owner of the roof cannot protest the actions of the owner of the courtyard, i.e., he may not demand that the owner of the courtyard refrain from construction that interferes with the former’s use of the projection. But the owner of the courtyard can protest the actions of the owner of the roof, and demand that the latter not build a projection of any size, even less than a handbreadth. He can also demand that the owner of the roof not use an existing projection, since it leads to damage caused by sight. And Rav Yehuda says: Even the owner of the courtyard cannot protest the actions of the owner of the roof.

The Gemara suggests: Shall we say that they disagree with regard to damage caused by sight? As one Sage, Rav Huna, holds that it is considered to be damage, and therefore the owner of the courtyard can protest, since the owner of the roof has the means to see into the other’s courtyard when using this projection, and one Sage, Rav Yehuda, holds that it is not considered to be damage.

The Gemara rejects this: No, everyone agrees that damage caused by sight is considered to be damage. And Rav Yehuda holds it is different here, as the owner of the roof can say to the owner of the courtyard: The projection is not suitable for use, since it is too small for me to stand upon and look into the courtyard. For what purpose is it suitable? To hang items on it, and nothing more. I will turn my face away and hang items on it without looking into your courtyard.

And the other amora, Rav Huna, holds that the owner of the courtyard can say to the owner of the roof: There may be times when you are frightened due to the height of the projection, and you will look into my courtyard while using it.

MISHNA: A person may not open his windows, i.e., build an opening in a wall to use as a window, into a courtyard belonging to partners, i.e., a courtyard in which he is a partner. If he purchased a house in another, adjacent courtyard, he may not open the house into a courtyard belonging to partners. If he built a loft on top of his house, he may not open it into a courtyard belonging to partners. Rather, if he desired to build a loft, he may build a room within his house, or he may build a loft on top of his house, and open it into his house, not directly into the courtyard.

GEMARA: With regard to the mishna’s ruling that one may not open a window into a courtyard that he co-owns, the Gemara asks: Why did the mishna specifically render it prohibited for one to open a window into a courtyard belonging to partners? One may not open a window into another’s courtyard either, as it will lead to damage caused by sight.

The Gemara replies that the mishna is speaking utilizing the style of: It is not necessary, as follows: It is not necessary to say that it is not permitted for one to open a window into another’s courtyard, where he is certainly not allowed to look; but where one wants to open a window into a courtyard belonging to partners, where the owner of the window can say to the other partner: Ultimately, since you need to conceal yourself from me and conduct yourself modestly in the courtyard where I too am a partner and have the right to be present, why does it bother you if I open a window into there? Therefore, the mishna teaches us that the partner may say to him: Until now I needed to conceal myself from you only when we were both in the courtyard. Now I will need to conceal myself from you even in the house, as you can see into my house from your window.

The Sages taught in a baraita: There was an incident involving a person who opened his windows into a courtyard belonging to partners and came before Rabbi Yishmael bar Rabbi Yosei, who said to him: You have established an acquired privilege, my son; you have established an acquired privilege, and you may not be prevented from using the windows. And he came before Rabbi Ḥiyya, who said to him: You toiled and opened the windows; you must toil and seal them, as the partners have the right to prevent you from using these windows.

Rav Naḥman said: