Gemara

(Mishnah): If one sells a house, the following are excluded: a Yatzi'a (a type of room), even if it opens into the house; an inner (storage) room...

(Chachamim of Bavel): A Yatzi'a is an Ofta (this will be explained).

(Rav Yosef): It is Bodka Chalila (a lean-to, i.e. a low house next to or in back of a house with many windows).

The first opinion agrees that if it has windows, (all the more so) it is not sold. The second opinion says that if it has no windows, it is sold.

(Rav Yosef): Yatzi'a, Tzela and Tei (chambers surrounding the Heichal) are all the same. It says "ha'Yatzi'a ha'Tachtonah Chamesh ba'Amah...", "veha'Tzela'os Tzela Al Tzela..." and "veha'Ta Kaneh Echad Orech..."

(Mar Zutra): The Yatzi'a is excluded only if it is at least four Amos.

Question (Ravina - Mishnah): A pit or cistern is not included, even if he wrote (that he sells) 'the depth and height';

Are they are included if they are less than four Amos?!

Answer (Mar Zutra): Those do not serve the same purpose as a house. A Yatzi'a is for dwelling. If it is large, it is important by itself, so it is not included with the house If it is small, it is not important by itself, and it is included.

(Mishnah): An inner room (for storing valuables).

Question: If the Yatzi'a is not included (even though it is for dwelling), there is no need to teach about the inner room!

Answer: It teaches that even if the seller delineated boundaries that include the room, it is not included.

65b (Beraisa): If one sells a house, he sells the door, latch... but not the key; a mortar affixed to the wall, funnel, Tanur, Kirayim or millstone.

If he said 'the house and everything inside', all these are included;

In any case, he did not include a pit, cistern or Yatzi'a.

Rishonim

Rif: An Ofta is an attic over a house. It has no opening to the outside. Its only opening is a hole in the roof of the house, which is its floor. People enter and leave through it. It is not for dwelling. This is why one may build it without consent of members of the Chatzer, for it does not lead to increased traffic. Rav Yosef excludes a room outside the wall of the house, like the cells around the Heichal. Some make it in the thickness of the wall. The Sugya is like Rav Yosef.

Ran (61a DH Mai, citing the Rashba): On 65b, a Beraisa excludes only a Yatzi'a. If he did not delineate the outer borders, even a room is excluded! If he delineates the borders, even a Yatzi'a is included! We must say like the Rif, that a Yatzi'a is an attic. Therefore, the borders do not indicate whether or not he included it.

Rambam (Hilchos Mechirah 25:1): One who sold his house did not sell the Yatzi'a around it, even if it opens to the house, i.e. if the Yatzi'a is four Amos or more. If it is less, it is included in the house. Similarly, an Aliyah that opens to the house through a hole in the roof is included with the house.

Rambam (2): One who sold his house did not sell the inner room, even if he delineated the outer borders.

Rosh (4:1): The Sugya is like Rav Yosef.

Piplulei Charifta (2): Perhaps this is because Rav Yosef taught that Yatzi'a, Tzela and Tei are all the same. However, 'Sugya' connotes that the support is not from what Rav Yosef himself taught.

Gra (CM 214:3): There is no support from Rav Yosef himself. They learn from 63b, which asks from the roof, but not from the Yatzi'a. In any case, the Rif and Rosh always rule like the latter opinion.

Rosh (ibid): Mar Zutra taught that the Yatzi'a is excluded only if it is at least four Amos. One may ask whether or not a room less than four Amos is excluded. Perhaps Mar Zutra taught about a Yatzi'a because a room need not be four Amos. Or, since we asked from a pit, and answered that it is excluded even if it is not four Amos because its use is very different than a house, we infer that a room, which is used like the house, is excluded only if it is four Amos. A room is excluded even if the seller delineated boundaries that include the room. One may ask whether or not the same applies to a Yatzi'a. Perhaps a room was taught 'needlessly', i.e. to teach that it is excluded even if it is within the boundaries, and the same applies to a Yatzi'a. Or, perhaps only for a room, which is important, we say that he merely gave known boundaries! Presumably, we do not distinguish.

Beis Yosef (CM 214 DH v'Al Mai): The Tur says that the Rosh equates a room to a Yatzi'a. He learns from the continuation of the Rosh, which says that delineating borders does not help for a room, and discusses whether it helps for a Yatzi'a. He concludes that we do not distinguish. The Tur understands that this refers also to the previous question about four Amos. The Ran says that a room is not sold even if it is less than four Amos. A Yatzi'a that is four Amos is not sold, and a room is even more important even if it is less than four Amos. This is why Mar Zutra did not teach about a room. It seems that the Rif and Rambam agree.

Beis Yosef (DH u'Mah she'Chosav v'Lo): The Rif and Rambam hold that delineating the borders does not help only regarding an inner room, but it could help for a Yatzi'a.

Poskim

Shulchan Aruch (CM 214:1): One who sold his house did not sell the Yatzi'a around it, even if it opens to the house.

SMA (2): I.e. even though it opens only to the house, it is not Batel to the house.

Beis Yosef (DH ha'Mocher): The Rashbam explains that Ofta is a low house next to or in back of a house. The Aruch explains like the Rif and Rambam, that Bodka Chalila is a balcony in back of the wall, above. The Rif, Rambam and Rosh rule like Rav Yosef. According to the Rashbam, any small building next to or in back of the house is included. According to the Rif and Rambam, it is not sold. The Rif and Rambam hold that an Aliyah on top of a house with an opening only to the house is sold with the house. It is not clear what the Rashbam holds about this. The Tur is very vague. He concludes 'the Rambam wrote that if the Aliyah is open to the house...', which connotes that also the Tur's initial words are like the Rambam. If so, he should have taught that a Yatzi'a, i.e. a small building near the house with windows for beauty, is not sold, but if it lacks windows, it is sold.

Beis Yosef (DH u'Mah she'Chosav Al): The Tur cites an opinion that an Aliyah is not included in a house. I did not find anyone say so explicitly. Perhaps he holds that the Rashbam holds like this, even though the Rashbam did not specify.

Rema: Some say that this is even if he delineated the outer borders.

Shulchan Aruch (ibid): This is if the Yatzi'a was four Amos or more. If it was less, it is included in the house (Rema - even if it is not open to the house.)

Gra (2): If it were excluded only when it is open to the house, the Gemara could not have asked from a pit or cistern.

Shulchan Aruch (ibid): Similarly, the Aliyah on the house that opens to the house through a hole in the roof is included with the house.

Beis Yosef (DH v'Al Mah): The Ramban did not decide whether or not delineating the borders helps for a Yatzi'a. The Nimukei Yosef says that the Ramban concluded like R. Yonah, that it does not. The Rif and Rambam mention delineating the outer borders only for a room, but not for a Yatzi'a. This connotes that they hold that it would help for a Yatzi'a.

Shulchan Aruch (2): One who sold his house did not sell the inner room, even if he delineated the outer borders.

Beis Yosef (DH uv'Mai): The Rashbam explains that the inner room is not used like the house. It is for storing things, like a box, therefore, is not included with the house. We say that he delineated larger borders for he thought that people do not recognize the precise borders.

SMA (6): The inner room is not for living, therefore, some say that even if it is not four Amos it is not sold. A Yatzi'a less than four within the borders is sold. The Rema is like the Rosh and Tur, who equate them.

Rema: Some say that this is only if the room is four Amos wide.

Gra (5): The Gemara asked that if a Yatzi'a is excluded, we need not teach about an inner room. We did not say that we must teach about an inner room less than four Amos.

Gra (6): The Yerushalmi says that it must be four by four.