Halacha

הלכה א
אֶחָד הַקּוֹנֶה מֵחֲבֵרוֹ חֲצִי שָׂדֵהוּ. אוֹ שְׁנַיִם שֶׁקָּנוּ מֵאֶחָד שָׂדֶה. אוֹ שֶׁיָּרְשׁוּ. אוֹ שֶׁנִּתְּנָה לָהֶן בְּמַתָּנָה. אוֹ שֶׁהֶחְזִיקוּ בָּהּ מִן הַהֶפְקֵר. אוֹ נִכְסֵי גֵּר. כְּלָלוֹ שֶׁל דָּבָר כָּל שֶׁיֵּשׁ בֵּינֵיהֶם שֻׁתָּפוּת בַּקַּרְקַע וּבִקֵּשׁ אֶחָד מִן הַשֻּׁתָּפִין לַחֲלֹק וְלִטּל חֶלְקוֹ לְבַדּוֹ. אִם יֵשׁ בְּאוֹתָהּ קַרְקַע דִּין חֲלוּקָה כּוֹפֶה אֶת שְׁאָר הַשֻּׁתָּפִין וְחוֹלְקִין עִמּוֹ. וְאִם אֵין בָּהּ דִּין חֲלוּקָה אֵין אֶחָד מֵהֶן יָכוֹל לָכֹף אֶת חֲבֵרוֹ לַחֲלֹק. וְכֵן הַדִּין בְּמִטַּלְטְלִין. בַּמֶּה דְּבָרִים אֲמוּרִים בְּשֶׁאֵין אֶחָד מֵהֶן מַכִּיר אֶת חֶלְקוֹ בַּמָּקוֹם שֶׁהֵן שֻׁתָּפִין בּוֹ אֶלָּא יַד כֻּלָּן מִשְׁתַּמֵּשׁ בְּכָל הַמָּקוֹם. אֲבָל אִם הָיָה אֶחָד מֵהֶן מַכִּיר חֶלְקוֹ אַף עַל פִּי שֶׁאֵין בָּהּ דִּין חֲלוּקָה כּוֹפֶה כָּל אֶחָד מֵהֶן אֶת חֲבֵרוֹ לְהַבְדִּיל בֵּין חֶלְקוֹ לְחֵלֶק חֲבֵרוֹ:
כסף משנה
1.
The following rules apply when a person purchases half of a field from a colleague, two people together purchase a field from a colleague, they both inherited a field, a field was given them as a gift, or they took possession of ownerless land or property belonging to a convert who died without leaving Jewish heirs - i.e., any situation in which two people own land in partnership.
If one of the partners asks to divide the property and take his portion alone, and the property is large enough to be divided, we compel the other partners to divide the property with him. If the property is not large enough to be divided, neither partner can require the other one to divide the property. Similar laws apply with regard to movable property.
When does the above apply? When neither of the parties recognizes a specific portion of the property they share as his own, but rather both use the entire property equally. If, however, one of the partners recognizes a portion of the property as his own, each one has the right to compel the other partner to make a divider between his portion and his colleague's portion, although the property is not large enough to be divided.

הלכה ב
אֶחָד מִן הַשֻּׁתָּפִין שֶׁאָמַר לַחֲבֵרוֹ בְּמָקוֹם שֶׁאֵין בּוֹ דִּין חֲלוּקָה. אוֹ בְּדָבָר שֶׁאִי אֶפְשָׁר שֶׁיַּחְלְקוּ כְּגוֹן שִׁפְחָה אוֹ כְּלִי. מְכֹר לִי חֶלְקְךָ בְּכָךְ וְכָךְ אוֹ קְנֵה מִמֶּנִּי כַּשַּׁעַר הַזֶּה. הַדִּין עִמּוֹ וְכוֹפִין אֶת הַנִּתְבָּע לִמְכֹּר לַחֲבֵרוֹ אוֹ לִקְנוֹת מִמֶּנּוּ. אֲבָל אִם אֵין הַתּוֹבֵעַ רוֹצֶה לִקְנוֹת אוֹ לֹא יִמְצָא בְּמָה יִקְנֶה. אֵינוֹ יָכוֹל לָכֹף אֶת חֲבֵרוֹ לִקְנוֹת מִמֶּנּוּ אֲפִלּוּ כַּשַּׁעַר הַזּוֹל. שֶׁהֲרֵי חֲבֵרוֹ יָכוֹל לוֹמַר לוֹ אֵין רְצוֹנִי שֶׁאֶקְנֶה אֶלָּא שֶׁאֶמְכֹּר. לְפִיכָךְ שְׁנֵי אַחִין אֶחָד עָנִי וְאֶחָד עָשִׁיר שֶׁהִנִּיחַ לָהֶם אֲבִיהֶם מֶרְחָץ אוֹ בֵּית הַבַּד. אִם עֲשָׂאָן הָאָב לְשָׂכָר הַשָּׂכָר לָאֶמְצַע כָּל זְמַן שֶׁיִּרְצוּ לַעֲמֹד בְּשֻׁתָּפוּת. עֲשָׂאָן הָאָב לְעַצְמוֹ אֵינוֹ יָכוֹל לָכֹף אָחִיו לְהַשְׂכִּיר אוֹתָם אֶלָּא מִשְׁתַּמְּשִׁין בָּהֶם כְּדֶרֶךְ שֶׁהִשְׁתַּמֵּשׁ אֲבִיהֶם. וַהֲרֵי עָשִׁיר אוֹמֵר לְעָנִי קַח לְךָ זֵיתִים וּבוֹא וַעֲשֵׂה אוֹתָם בְּבֵית הַבַּד. קְנֵה לְךָ עֲבָדִים וְיָבוֹאוּ וְיִרְחֲצוּ בַּמֶּרְחָץ. וְאֵין הֶעָנִי כּוֹפֶה אֶת הֶעָשִׁיר לִקְנוֹת חֶלְקוֹ אֶלָּא אִם כֵּן אָמַר לוֹ קְנֵה מִמֶּנִּי אוֹ מְכֹר לִי וַהֲרֵינִי לוֹוֶה וְקוֹנֶה אוֹ מוֹכֵר לַאֲחֵרִים וְקוֹנִין הַדִּין עִמּוֹ. אָמַר כָּל אֶחָד מֵהֶן אֵינִי קוֹנֶה אֶלָּא הֲרֵינִי מוֹכֵר חֶלְקִי מוֹכְרִין אוֹתָהּ לַאֲחֵרִים. אָמַר כָּל אֶחָד מֵהֶם אֵינִי מוֹכֵר אֶלָּא כָּל אֶחָד מֵהֶן רוֹצֶה שֶׁיִּקְנֶה חֵלֶק חֲבֵרוֹ. אוֹ שֶׁאֵין אֶחָד מֵהֶן רוֹצֶה לֹא לִקְנוֹת חֵלֶק חֲבֵרוֹ וְלֹא לִמְכֹּר חֶלְקוֹ אֶלָּא יִשָּׁאֲרוּ שֻׁתָּפִין בַּגּוּף. הֵיאַךְ הֵן עוֹשִׂין. אִם הָיָה הַמָּקוֹם עָשׂוּי לְשָׂכָר מַשְׂכִּירִין אוֹתוֹ וְחוֹלְקִין שְׂכָרוֹ. וְאִם אֵינוֹ עָשׂוּי לְשָׂכָר אִם חָצֵר הוּא שׁוֹכְנִין בָּהּ שָׁנָה שָׁנָה שֶׁאִי אֶפְשָׁר שֶׁיִּשְׁכְּנוּ שְׁנֵיהֶם כְּאַחַת מִפְּנֵי הֶזֵּק רְאִיָּה שֶׁהֲרֵי אֵין בָּהּ דִּין חֲלוּקָה וְאֵין אָדָם עָשׂוּי לִטְרֹחַ כָּל שְׁלֹשִׁים יוֹם לִפְנוֹת מֵחָצֵר לֶחָצֵר אֶלָּא מִשָּׁנָה לְשָׁנָה. וְאִם מֶרְחָץ הוּא נִכְנָסִין לָהּ שְׁנֵיהֶם תָּמִיד בְּכָל יוֹם. וְכֵן כָּל דָּבָר שֶׁרָאוּי לְהִשְׁתַּמֵּשׁ בּוֹ תָּמִיד וְאֵינוֹ עָשׂוּי לְשָׂכָר כְּגוֹן מֶרְחָץ אוֹ מַצָּע אוֹ סֵפֶר תּוֹרָה אֵינוֹ יָכוֹל לוֹמַר לוֹ הִשְׁתַּמֵּשׁ אַתָּה יוֹם וַאֲנִי יוֹם שֶׁהֲרֵי אוֹמֵר לוֹ בְּכָל יוֹם אֲנִי רוֹצֶה לְהִשְׁתַּמֵּשׁ בּוֹ:
כסף משנה
2.
In a situation where the property is not large enough to be divided or with regard to an entity that cannot be divided - e.g., a maidservant or a utensil - if one of the partners tells the other: "Sell me your portion for this and this much, or buy my portion for the same price," his request is supported by the law. We compel the other partner either to sell his share to his colleague or to purchase his colleague's share from him.
If, however, the other partner does not desire to purchase his partner's share or does not have the means to do so, he cannot compel his colleague to purchase his share from him even at the low market price. For his colleague may tell him: "I do not want to buy; I want to sell."
Therefore, the following laws apply if two brothers, one rich and one poor, inherited from their father a bathhouse or an olive press. If the father made these premises for the purpose of hire, the two share the rental equally for as long as they desire to remain partners.
If the father made these structures for his personal use, the poor brother cannot force the rich brother to hire them out. Instead, they should use them as their father used them. The rich brother can tell the poor brother: "Purchase olives and crush them in the olive press; purchase servants and have them come and wash in the bathhouse."
The poor brother cannot compel the rich brother to purchase his portion unless the poor brother tells him: "Purchase my portion from me or sell me your portion. For I will borrow from others and purchase it or sell it to others, and they will purchase it." If he makes such statements, his claim is supported by law.
If each of the brothers says: "I don't want to purchase your portion; I want to sell my portion," the property should be sold to others.
The following rules apply if both of them say: "I will not sell," but instead each of them wishes to purchase his colleague's portion, or neither of them desires to purchase his colleague's portion, nor to sell his own portion, but instead to remain partners in the property.
What should they do? If the place was fit to rent, they should hire it out and divide the rent. If the place was not fit to rent they should alternate. If the property is a courtyard, they should dwell in it, each for a year at a time. The rationale for this ruling is that it is impossible for them to dwell in it together, because of the lack of privacy, and it is not large enough to divide. A more frequent rotation is not employed, because a person would not trouble himself to move from one courtyard to another every 30 days. Hence, the rotation is carried out from year to year.
If the shared property is a bathhouse, both of them are allowed to enter at all times during the day. The same principle applies to any object that is fit to be used at all times and is not usually hired out - e.g., a bathhouse, a mattress or a Torah scroll. One cannot tell the other: "You use it one day, and I will use it the next day." For the other can claim: "I want to use it every day."

הלכה ג
אֶחָד הַשּׂוֹכֵר מֵחֲבֵרוֹ מִקְצָת חָצֵר. אוֹ שָׂדֶה שֶׁאֵין בָּהּ דִּין חֲלוּקָה. אוֹ שְׁנַיִם שֶׁשָּׂכְרוּ מָקוֹם אֶחָד בְּשֻׁתָּפוּת. כָּל אֶחָד מֵהֶן יָכוֹל לָכֹף אֶת חֲבֵרוֹ וְלוֹמַר לוֹ אוֹ שְׂכֹר מִמֶּנִּי חֶלְקִי אוֹ הַשְׂכִּיר לִי חֶלְקְךָ. וְאִם יֵשׁ בָּהּ דִּין חֲלוּקָה חוֹלְקִין:
כסף משנה
3.
When one person rents from a colleague a portion of a courtyard or a field that is not large enough to divide or two people rent such a property in partnership, each one can compel his colleague and tell him: "Either rent my portion from me or rent me your portion." If the property is large enough to divide, it should be divided.

הלכה ד
אֵי זֶהוּ דִּין חֲלוּקָה. כָּל שֶׁאִלּוּ יְחַלֵּק לְפִי הַשֻּׁתָּפִין יַגִּיעַ לַפָּחוּת שֶׁבָּהֶם חֵלֶק שֶׁשֵּׁם הַכּל קָרוּי עָלָיו. אֲבָל אִם אֵין שֵׁם הַכּל נִקְרָא עַל הַחֵלֶק אֵין בָּהּ דִּין חֲלוּקָה. כֵּיצַד. כָּל חָצֵר שֶׁאֵין בָּהּ אַרְבַּע אַמּוֹת עַל אַרְבַּע אַמּוֹת אֵינָהּ קְרוּיָה חָצֵר. וְכָל שָׂדֶה שֶׁאֵין בָּהּ כְּדֵי זְרִיעַת תִּשְׁעָה קַבִּין אֵינָהּ קְרוּיָה שָׂדֶה. וְכָל גִּנָּה שֶׁאֵין בָּהּ כְּדֵי זְרִיעַת חֲצִי קַב אֵינָהּ קְרוּיָה גִּנָּה. וְכָל פַּרְדֵּס שֶׁאֵין בּוֹ כְּדֵי זְרִיעַת שְׁלֹשָׁה קַבִּין אֵינוֹ קָרוּי פַּרְדֵּס. לְפִיכָךְ אֵין חוֹלְקִין אֶת הֶחָצֵר עַד שֶׁיִּהְיֶה אַרְבַּע אַמּוֹת לְכָל אֶחָד וְאֶחָד מִן הַשֻּׁתָּפִין. וְלֹא אֶת הַשָּׂדֶה עַד שֶׁיִּהְיֶה בָּהּ כְּדֵי זְרִיעַת תִּשְׁעָה קַבִּין [לְכָל אֶחָד וְאֶחָד]. וְלֹא אֶת הַגִּנָּה עַד שֶׁיְּהֵא בָּהּ חֲצִי קַב לְכָל אֶחָד וְאֶחָד. וְלֹא אֶת הַפַּרְדֵּס עַד שֶׁיְּהֵא בּוֹ בֵּית שְׁלֹשָׁה קַבִּין לְכָל אֶחָד וְאֶחָד. בַּמֶּה דְּבָרִים אֲמוּרִים בְּאֶרֶץ יִשְׂרָאֵל וְכַיּוֹצֵא בָּהּ. אֲבָל בְּבָבֶל וְכַיּוֹצֵא בָּהּ אֵין חוֹלְקִין אֶת הַשָּׂדֶה עַד שֶׁיִּהְיֶה בָּהּ כְּדֵי חֲרִישַׁת יוֹם לָזֶה וַחֲרִישַׁת יוֹם לָזֶה. וְלֹא אֶת הַפַּרְדֵּס עַד שֶׁיִּהְיֶה בּוֹ שְׁלֹשִׁים וְשִׁשָּׁה אִילָנוֹת לָזֶה [וּשְׁלֹשִׁים וְשִׁשָּׁה אִילָנוֹת לָזֶה] כְּדֵי עֲבוֹדַת אָדָם אֶחָד בַּיּוֹם אֶחָד. וְשָׂדֶה שֶׁמַּשְׁקִין אוֹתָהּ בִּכְלִי עַד שֶׁיְּהֵא בָּהּ כְּדֵי שֶׁיְּמַלֵּא הַפּוֹעֵל יוֹם אֶחָד לָזֶה וְיוֹם אֶחָד לָזֶה:
כסף משנה
4.
What is meant by a property being large enough to divide? That if it were divided among the partners, even the partner with the smallest share would receive a portion of the property large enough to be referred to by the same name that is used to refer to the entire entity. If, however, the name that is used to refer to the entire entity would not be used for this portion, it is not large enough to divide.
What is implied? Whenever a courtyard does not contain four cubits by four cubits, it cannot be called a courtyard. Whenever a field is not large enough to sow nine kabbim of grain, it is not considered to be a field. Whenever a garden is not large enough to sow a half a kav, it is not considered to be a garden. Whenever an orchard is not large enough to sow three kabbim, it is not considered to be an orchard.
Therefore, a courtyard is not divided among partners unless it is large enough for each of the partners to receive at least four cubits by four cubits. A field is not divided unless it is large enough for each of the partners to receive at least enough to sow nine kabbim. A garden is not divided unless it is large enough for each of the partners to receive at least enough to sow half a kav. And an orchard is not divided unless it is large enough for each of the partners to receive at least enough to sow three kabbim.
Where does the above apply? In Eretz Yisrael and lands like it. In Babylonia and lands like it, by contrast each partner must receive a larger measure. A field is not divided unless it is large enough for each of the partners to receive at least enough to require a day of plowing. An orchard is not divided unless it is large enough for each of the partners to receive at least 36 trees - this is the number that requires one person to tend to them for a day. A field that is watered with a utensil is not divided unless it is large enough for each of the partners to receive at least enough that a workman will spend a day watering it.

הלכה ה
אֵין חוֹלְקִין אֶת הַטְּרַקְלִין וְלֹא אֶת הַמּוֹרָן וְלֹא אֶת הַשּׁוֹבָךְ וְלֹא אֶת בֵּית הַבַּד וְלֹא אֶת הַמֶּרְחָץ וְלֹא אֶת הַטַּלִּית עַד שֶׁיְּהֵא בְּכָל חֵלֶק מֵהֶן כְּדֵי לָזֶה וּכְדֵי לָזֶה. אִם מֶרְחָץ חָלְקוּ עַד שֶׁיְּהֵא בְּכָל חֵלֶק מֵהֶן כְּדֵי מֶרְחָץ. וְאִם שׁוֹבָךְ עַד שֶׁיְּהֵא כָּל חֵלֶק שׁוֹבָךְ בִּפְנֵי עַצְמוֹ. וְכֵן בְּטַלִּית וּבִשְׁאָר כָּל הַדְּבָרִים. אֵין בָּהֶן כְּדֵי לָזֶה וּכְדֵי לָזֶה מַעֲלִין אוֹתוֹ בְּדָמִים וְיֵשׁ [לוֹ] לוֹמַר לַחֲבֵרוֹ אוֹ מְכֹר לִי אוֹ קְנֵה מִמֶּנִּי. אָמַר אֶחָד מֵהֶן חֲלֹק זֶה אַף עַל פִּי שֶׁאֵין הַחֲלָקִין שָׁוִים אֲנִי אֶטּל אֶת הַפָּחוּת וְטל אַתָּה אֶת הַיֶּתֶר אֵין שׁוֹמְעִין לוֹ שֶׁהֲרֵי אוֹמֵר לוֹ אֵין רְצוֹנִי לִקַּח מַתָּנָה. אֶלָּא הוֹאִיל וְאֵין בָּהּ דִּין חֲלוּקָה בְּשָׁוֶה הֲרֵי אָנוּ מַעֲלִין בְּדָמִים:
כסף משנה
5.
One should not divide a hall, a large building, a dovecote, an olive press, a bathhouse or a garment unless each of the recipients will receive a portion sufficient for himself. If one is dividing a bathhouse, each portion must be useful as a bathhouse. If one is dividing a dovecote, each portion must be useful as a dovecote. The same principles apply with regard to a garment or other objects.
If the entity is not large enough to divide, its value is assessed. One can tell one's fellow partner: "Either sell it to me or buy it from me."
If the entity is not large enough to divide, but one partner says to the other: "Let us divide this even though the portions are not equal. I will take the smaller portion and you take the larger portion," we are not required to accept his proposition. For the other partner will tell him: "I do not desire to receive a gift." Instead, since the entity is not large enough for an equal division, we assess its financial value.

קניין הלכות שכנים פרק א
Kinyan Shcheinim Chapter 1