Siman 59
Presented here for study, not as a practical ruling. The Shulchan Aruch rules by Sephardi custom, the Rema's glosses by Ashkenazi custom, and the Kitzur follows Ashkenazi custom. For a practical question, ask your rabbi.
א הַמַּשִּׂיא בְּנוֹ גָּדוֹל בְּבַיִת, קָנָה הַבַּיִת; וְהוּא שֶׁיִּהְיוּ נִשּׂוּאִין רִאשׁוֹנִים לְזֶה הַבֵּן, וְלֹא הִשִּׂיא הָאָב בֵּן זָכָר אַחֵר קֹדֶם לוֹ, וְלֹא שִׁיֵּר הָאָב בְּזֶה הַבַּיִת שֶׁיִּחֵד לוֹ, כְּלוּם. אֲבָל אִם שִׁיֵּר שָׁם אֲפִלּוּ פַּךְ אֶחָד, לֹא קָנָה הַבַּיִת. וְיֵשׁ אוֹמְרִים דְּבָעִינָן גַּם כֵּן שֶׁיַּשִּׂיא לוֹ בְּתוּלָה, וְשֶׁיְּהֵא לָאָב בַּיִת אַחֵר לָדוּר בּוֹ (טוּר):
1 When the eldest son in the house marries, he acquires the house. And if another son marries first and his father does not marry off the eldest son until after him, and the father does not leave anything in the house, it is his [the married son's] alone. But if one leaves even one jug, he does not acquire the house. Some say that if he does not marry a virgin, the father may remain in the house to live in it (Tur).
ב יִחֵד לוֹ בַּיִת וּכְלֵי בַּיִת, אַף עַל פִּי שֶׁשִּׁיֵּר בַּבַּיִת כְּלִי אֶחָד לְעַצְמוֹ, אוֹ הָיָה לוֹ שָׁם אוֹצָר וְכַיּוֹצֵא בּוֹ, קָנָה כְּלֵי הַבַּיִת, אֲבָל הַבַּיִת לֹא קָנָה:
2 If he combines a house and vessels of the house, even if one vessel that is his remains in house, or had a treasure or anything like that, he acquires the vessels of the house, but not the house itself.
ג יִחֵד לוֹ בַּיִת וַעֲלִיָּה; בַּיִת קָנָה, עֲלִיָּה לֹא קָנָה. וְכֵן אִם יִחֵד לוֹ בַּיִת וְאַכְסַדְרָה; בַּיִת קָנָה, אַכְסַדְרָה לֹא קָנָה:
3 If he designated for him (his son) a house and attic, the son acquires the house but not the attic. Similarly if he designated a house and portico, he acquires the house but not the portico.
ד שְׁנֵי בָּתִּים זוֹ לִפְנִים מִזּוֹ, לֹא קָנָה אֶלָּא הָאֶחָד שֶׁנָּשָׂא בּוֹ:
4 If there were two houses, one interior to the other, he acquires only the house in which the marriage took place.