Halacha

הלכה א
מִי שֶׁהָיְתָה לוֹ עֲלִיָּה לְמַעְלָה מִבֵּיתוֹ שֶׁל חֲבֵרוֹ וְנָפַל כֹּתֶל מִכָּתְלֵי הַבַּיִת אֵין בַּעַל הָעֲלִיָּה נוֹתֵן לוֹ כְּלוּם בִּיצִיאוֹתָיו וְכוֹפֶה אֶת בַּעַל הַבַּיִת לִבְנוֹתוֹ כְּשֶׁהָיָה. אֲבָל אֵין בַּעַל הַבַּיִת כּוֹפֶה לְבַעַל הָעֲלִיָּה לִבְנוֹת כֹּתֶל עֲלִיָּה שֶׁנָּפַל. וְהַתִּקְרָה שֶׁל בַּיִת הֲרֵי הִיא שֶׁל בַּעַל הַבַּיִת וְהַמַּעֲזִיבָה שֶׁעַל הַתִּקְרָה הֲרֵי הִיא שֶׁל בַּעַל הָעֲלִיָּה:
כסף משנה
1.
The following rules apply when a person owns a loft that is situated above a house belonging to a colleague. If one of the walls of the house falls, the owner of the loft is not required to pay any of the costs incurred by the owner of the house in repairing it. And he may compel the owner of the house to repair it as it was originally. If, by contrast, one of the walls of the loft falls, the owner of the house cannot compel the owner of the loft to repair it.
The ceiling is the responsibility of the owner of the house. The plaster above it is the responsibility of the owner of the loft.

הלכה ב
נָפְלוּ שְׁנֵיהֶם הַבַּיִת וְהָעֲלִיָּה הֲרֵי שְׁנֵיהֶם חוֹלְקִין בָּעֵצִים וּבַאֲבָנִים וּבֶעָפָר. וְאִם נִשְׁתַּבְּרוּ מִקְצָת הָאֲבָנִים רוֹאִין אֵי זוֹ רְאוּיָה לְהִשְׁתַּבֵּר אִם אַבְנֵי הַבַּיִת אוֹ אַבְנֵי הָעֲלִיָּה. וְדָבָר זֶה יָדוּעַ מִדֶּרֶךְ הַנְּפִילָה אִם נָפַל הָעֶלְיוֹן עַל הַתַּחְתּוֹן וַהֲרָסוֹ אוֹ נִשְׁמַט הַתַּחְתּוֹן וְנָפַל הָעֶלְיוֹן וְנֶהֱרַס. וְאִם אֵינָן יוֹדְעִין כֵּיצַד נָפַל חוֹלְקִין הָאֲבָנִים הַשְּׁלֵמוֹת וְהַשְּׁבוּרוֹת:
כסף משנה
2.
If both the house and the loft fall, both owners share equally in the wood, the stones and the sand.
If some of the stones are broken, we determine which of the stones were more likely to have broken, the stones of the house or the stones of the loft. This can be determined by the manner in which the stones fell: whether the upper stones fell on the lower stones and destroyed them or the lower stones slipped out and the upper stones fell and were destroyed. If it cannot be determined how the stones fell, both the whole stones and the broken stones should be divided equally.

הלכה ג
אָמַר בַּעַל הָעֲלִיָּה לְבַעַל הַבַּיִת לִבְנוֹת כְּדֵי שֶׁיִּבְנֶה עֲלִיָּתוֹ עַל גַּבָּיו וְהוּא אֵינוֹ רוֹצֶה הֲרֵי בַּעַל הָעֲלִיָּה בּוֹנֶה אֶת הַבַּיִת כְּשֶׁהָיָה. וְיוֹשֵׁב וְדָר בְּתוֹכוֹ עַד אֲשֶׁר יִתֵּן כָּל יְצִיאוֹתָיו וְאַחַר כָּךְ יֵצֵא וְיִבְנֶה עֲלִיָּתוֹ אִם רוֹצֶה:
כסף משנה
3.
The following rule applies when both structures fall, and the owner of the loft tells the owner of the house to rebuild his home so that he can build his loft upon it, but the owner of the home refuses to do so. The owner of the loft may rebuild the home to its original size and live inside it until the owner of the home reimburses him for all his costs. Then he must leave, and he may build his loft upon it if he desires.

הלכה ד
וְאִם אֵין אֶחָד מֵהֶן יָכוֹל לִבְנוֹת בַּעַל הָעֲלִיָּה נוֹטֵל שְׁלִישׁ הַקַּרְקַע וּבַעַל הַבַּיִת שְׁנֵי שְׁלִישִׁים:
כסף משנה
4.
If neither of them is able to rebuild the building, the owner of the loft receives one third of the land, and the owner of the house receives two thirds of the land.

הלכה ה
רָצָה בַּעַל הַבַּיִת לִבְנוֹת בֵּיתוֹ בּוֹנֶה כְּשֶׁהָיָה. וְאִם בָּא לְשַׁנּוֹת בַּכְּתָלִים אִם חִזֵּק אוֹתָן וְהִרְבָּה בְּרָחְבָּן יוֹתֵר מִמַּה שֶּׁהָיוּ שׁוֹמְעִין לוֹ. רָצָה לְמַעֵט בְּרָחְבָּן אוֹ לִפְחוֹת מֵחָזְקָן כְּגוֹן שֶׁהָיוּ אֲבָנִים וּבִקֵּשׁ לְהַחְזִיר לְבֵנִים וְכַיּוֹצֵא בָּהֶן אֵין שׁוֹמְעִין לוֹ. בָּא לְשַׁנּוֹת אֶת הַתִּקְרָה לְקוֹרוֹת כְּבֵדִין וַחֲזָקִין שׁוֹמְעִין לוֹ. לִפְחוֹת בְּרָחְבָּן פָּחוֹת מִמַּה שֶּׁהָיוּ אֵין שׁוֹמְעִין לוֹ. הִרְבָּה בְּחַלּוֹנוֹת אוֹ שֶׁהוֹסִיף בְּגֹבַהּ הַבַּיִת אֵין שׁוֹמְעִין לוֹ. מִעֵט בְּחַלּוֹנוֹת אוֹ שֶׁמִּעֵט בְּגֹבַהּ הַבַּיִת שׁוֹמְעִין לוֹ. וְכֵן בַּעַל הָעֲלִיָּה בּוֹנֶה אוֹתָהּ אִם רָצָה כְּשֶׁהָיְתָה. וְאִם בָּא לְשַׁנּוֹת הַכְּתָלִים לְהַרְחִיב וּלְהַחְזִיק אֵין שׁוֹמְעִין לוֹ מִפְּנֵי שֶׁהוּא מַכְבִּיד עַל כֹּתֶל הַתַּחְתּוֹן. אֲבָל לְמַעֵט שׁוֹמְעִין לוֹ. וְכֵן בְּקוֹרוֹת תִּקְרָה הָעֶלְיוֹנָה אִם שִׁנָּה אוֹתָם לְקַלִּים מִמַּה שֶּׁהָיוּ שׁוֹמְעִין לוֹ. לִכְבֵדִים מֵהֶן אֵין שׁוֹמְעִין לוֹ. הִרְבָּה בְּחַלּוֹנוֹת אוֹ שֶׁמִּעֵט בְּגֹבַהּ הָעֲלִיָּה שׁוֹמְעִין לוֹ. אֲבָל אִם מִעֵט בְּחַלּוֹנוֹת אוֹ הִרְבָּה בְּגָבְהָהּ אֵין שׁוֹמְעִין לוֹ:
כסף משנה
5.
If the owner of the house desires to rebuild his home, he should rebuild it as it was originally. The following laws apply if he desires to change the structure of the walls: If he desires to strengthen them and increase their width beyond their previous measures, his desire is heeded. If he desires to make them narrower or weaker - e.g., originally, they had been made from stone, and now he wants to make them from bricks - his desire is not heeded.
If he desires to build the ceiling with heavier and stronger beams, his desire is heeded. If he desires to make them narrower than they were originally, his desire is not heeded.
If he desires to add more windows or increase the height of the house, his desire is not heeded. If he desires to reduce the number of windows or diminish the height of the house, his desire is heeded.
Similarly, the owner of the loft should rebuild it as it was originally. If he desires to change the structure of the walls, to increase their width and strengthen them, his desire is not heeded, because he places an additional burden on the lower walls. If he desires to make them narrower, his desire is heeded.
Similar laws apply with regard to the beams of the ceiling of the loft. If he desires to exchange them for lighter ones, his desire is heeded. If he desires to use heavier beams, his desire is not heeded.
If he desires to add more windows or diminish the height of the loft, his desire is heeded. If he desires to reduce the number of windows or increase the height of the house, his desire is not heeded.

הלכה ו
נִתְדַּלְדְּלוּ קוֹרוֹת הַבַּיִת וְיָרְדוּ לַאֲוִיר הַבַּיִת אִם הִגִּיעוּ לְתוֹךְ עֲשָׂרָה טְפָחִים סוֹתֵר וּבוֹנֶה. וְאִם לֹא הִגִּיעוּ יָכוֹל בַּעַל הָעֲלִיָּה לְעַכֵּב עָלָיו. וַאֲפִלּוּ אָמַר לוֹ בַּעַל הַבַּיִת אֲנִי אֶשְׂכֹּר לְךָ מָקוֹם כְּדֵי שֶׁתָּדוּר בּוֹ עַד שֶׁאֲתַקֵּן הַתִּקְרָה אֵין שׁוֹמְעִין לוֹ שֶׁהֲרֵי אוֹמֵר לוֹ אֵינִי רוֹצֶה שֶׁאֶטְרַח מִמָּקוֹם לְמָקוֹם כְּדֵי שֶׁתְּתַקֵּן אֶת בֵּיתְךָ:
כסף משנה
6.
The following rules apply when the beams of the ceiling sink lower and descend into the space of the house. If they reach within ten handbreadths of the ground, the owner of the house may destroy and rebuild the entire structure. If they do not reach that low, the owner of the loft may prevent him from doing so. Even if the owner of the house tells the owner of the loft: "I will rent you another place to live until I repair the ceiling," his desire is not heeded. For the owner of the loft will tell him: "I do not want the difficulty of moving from place to place so that you can repair your home."

הלכה ז
הִתְנוּ בֵּינֵיהֶם עַל דָּבָר זֶה. אִם נִשְׁאַר בְּגֹבַהּ הַבַּיִת כְּדֵי שֶׁיִּקַּח אָדָם חֲבִילָה בֵּינוֹנִית עַל רֹאשׁוֹ וְיִכָּנֵס בָּהּ תַּחַת קוֹרוֹת אֵלּוּ שֶׁנֶּעֶקְמוּ אֵינוֹ סוֹתֵר. וְאִם אֵינוֹ יָכוֹל לְהִכָּנֵס בָּהּ עַד שֶׁיָּכֹף אֶת רֹאשׁוֹ סוֹתֵר וּמְתַקֵּן וּבוֹנֶה. וְאֵין בַּעַל הָעֲלִיָּה יָכוֹל לְעַכֵּב שֶׁהֲרֵי הִתְנוּ בֵּינֵיהֶם תְּחִלָּה:
כסף משנה
7.
If an agreement was made between the two of them that as long as the house is high enough that a person can enter while carrying an ordinary sized burden on his head despite the fact that the beams have bent lower, the owner may not tear it down. If, however, he cannot enter while carrying such a burden unless he bends his head, he may tear it down, repair it and rebuild it, then the owner of the loft may not prevent him. For this was the agreement they made at the outset.

הלכה ח
בֵּית הַבַּד שֶׁהוּא בָּנוּי בָּעֳבִי הָהָר וְגִנָּה אַחַת עַל גַּבָּיו. וְנִפְחֲתוּ שְׁמֵי בֵּית הַבַּד כְּאַרְבָּעָה טְפָחִים אוֹ יוֹתֵר. הֲרֵי בַּעַל הַגִּנָּה יוֹרֵד וְזוֹרֵעַ לְמַטָּה עַד שֶׁיַּעֲשֶׂה זֶה לַבַּיִת בַּדוֹ כֵּיפִין. וִיתַקֵּן הָעֶלְיוֹן קַרְקַע גִּנָּתוֹ וְיִזְרַע כָּל גִּנָּתוֹ:
כסף משנה
8.
The following rule applies when an olive press is built in the midst of a mountain, a garden is located upon it, and then the top of the olive press becomes opened four handbreadths or more. The owner of the garden may descend and sow the earth of the olive press until the owner of the olive press makes a covering for the olive press, so that the owner of the higher property can restore the earth of his garden and sow it.

הלכה ט
שְׁתֵּי גִּנּוֹת זוֹ עַל גַּב זוֹ וְהַיָּרָק בֵּינְתַיִם בְּגֹבַהּ עֳבִי הָאָרֶץ שֶׁבֵּינֵיהֶם. כָּל שֶׁהָעֶלְיוֹן יָכוֹל לִפְשֹׁט אֶת יָדוֹ וְלִטּל אוֹתוֹ מֵעִקָּרוֹ הֲרֵי הוּא שֶׁלּוֹ וּבִלְבַד שֶׁלֹּא יֶאֱנֹס אֶת עַצְמוֹ וְהַשְּׁאָר שֶׁל תַּחְתּוֹן. הָיָה מַגִּיעַ לְנוֹפוֹ וְאֵינוֹ מַגִּיעַ לְעִקָּרוֹ לֹא יִטּל הָעֶלְיוֹן וְאִם נָטַל אֵין מוֹצִיאִין אוֹתוֹ מִיָּדוֹ. אֲבָל הָאִילָן הָעוֹמֵד עַל הַמֵּצַר אַף עַל פִּי שֶׁהוּא נוֹטֶה לְתוֹךְ שָׂדֶה אַחַת מֵהֶן הֲרֵי שְׁנֵיהֶם חוֹלְקִין בְּפֵרוֹתָיו:
כסף משנה
9.
The following rules apply when there are two gardens, one on top of the other on the slope of a mountain, and there are vegetables growing on the surface of the earth between them. Any vegetables to which the owner of the higher property can extend his hand and pull out by their roots belong to him, provided he does not strain himself. The remainder belong to the owner of the lower property.
If the owner of the higher property can reach the leaves of the vegetables, but cannot reach their roots, he should not take them. If, however, he does take them, they should not be expropriated from his possession.
Different laws apply with regard to a tree that stands on the boundary line between two properties. Even though it leans into the field belonging to one of them, both of them may divide the fruits.

הלכה י
שָׁטַף נָהָר אֶת זֵיתָיו וּשְׁתָלָם בְּתוֹךְ שְׂדֵה חֲבֵרוֹ וְאָמַר הַלָּה זֵיתַי אֲנִי נוֹטֵל אֵין שׁוֹמְעִין לוֹ מִשּׁוּם יִשּׁוּב הָאָרֶץ אֶלָּא יַעַמְדוּ בִּמְקוֹמָן. וְאִם עֲקָרָן הַנָּהָר בְּגוּשֵׁיהֶן כְּשֶׁשְּׁתָלָן יַחְלְקוּ הַפֵּרוֹת בַּעַל הַשָּׂדֶה עִם בַּעַל הַזֵּיתִים כָּל שָׁלֹשׁ שָׁנִים וּלְאַחַר שָׁלֹשׁ הַכּל לְבַעַל הַשָּׂדֶה. וְאִם לֹא נֶעֶקְרוּ בְּגוּשֵׁיהֶן הַכּל לְבַעַל הַקַּרְקַע מִיָּד:
כסף משנה
10.
The following rules apply if a river washes away olive trees belonging to one person and plants them in a field belonging to another. If the owner of the trees says: "I want to take my olive trees, his desire is not heeded, in order that the land be settled. Instead, they should remain in their place.
If the river uproots the trees together with their earth when it replants them, the owner of the field and the owner of the olive trees should divide the fruit for the first three years. After three years, all the produce belongs to the owner of the field. If they were not uprooted together with their earth, the owner of the field is entitled to the entire benefit immediately.

הלכה יא
כַּיּוֹצֵא בּוֹ הַמּוֹכֵר זֵיתָיו לְעֵצִים אִם פָּסַק עִמּוֹ לָקֹץ מִיַּד כָּל הַפֵּרוֹת שֶׁיַּעֲשׂוּ הֲרֵי הֵן לְבַעַל הַקַּרְקַע. וְאִם הִתְנָה עִמּוֹ לָקֹץ כָּל זְמַן שֶׁיִּרְצֶה כָּל הַפֵּרוֹת שֶׁיּוֹצִיאוּ לְבַעַל הָעֵצִים. מָכַר סְתָם אִם עָשׂוּ פָּחוֹת מֵרְבִיעִית לִסְאָה חוּץ מִן הַהוֹצָאָה הֲרֵי אֵלּוּ שֶׁל בַּעַל הַזֵּיתִים. עָשׂוּ רְבִיעִית לִסְאָה חוּץ מִן הַהוֹצָאָה הֲרֵי אֵלּוּ יַחֲלֹקוּ:
כסף משנה
11.
Similar concepts apply when a person sells his olive trees to be used as wood. If the agreement was that he would cut them down immediately, all the fruit they produce belongs to the owner of the land. If the agreement was that he could cut them down whenever he desires, all the fruit they produce belongs to the owner of the trees.
The following rules apply when the trees were sold without a specific agreement. If they produce no more than a revi'it per se'ah beyond the costs involved, they belong to the owner of the olive trees. If they produce more than a revi'it per se'ah beyond the costs involved, they should be divided.

קניין הלכות שכנים פרק ד
Kinyan Shcheinim Chapter 4