Halakhah su Levitico 25:31

That is that He commanded us to return all the lands to their owners in this year, and that they go out from their buyers without [payment]. And that is His, may He be blessed, saying "And in all the land of your possession, you shall grant a redemption for the land" (Leviticus 25:24). And He explained to us that this redemption be in this year; and that is His saying, "In the year of this Jubilee" (Leviticus 25:13). And Scripture has already been exacting about its commandments and explained what the law would be like for the seller and the buyer, if [the seller] wants to redeem his inheritance - that was sold - before the Jubilee year. And it explained further and said that this law is particular to the lands that are outside the city wall; and that the law of the houses built in the fields is exactly [like] the law of the orchards and gardens - since they are not built within the wall. And these are the houses of the villages (chatzerim), about which Scripture said, "it shall be considered as a field of the land" (Leviticus 25:31). And the regulations of this commandment have already been explained in Arakhin. But it too is only practiced in the Land of Israel, and at the time when Jubilee is practiced. (See Parashat Behar; Mishneh Torah, Sabbatical Year and the Jubilee 10.)

And regarding the difference of houses from fields, we have already written their law later in its place (Sefer Hachinukh 340) - that the law of the houses of open (unwalled) towns is like the field of holding - meaning, that they [can also be redeemed] against the buyer's will; as it is written (Leviticus 25:31), "it may be redeemed." And their power is greater than the fields, in that they can be redeemed even within the [first] year, like the law of houses of walled cities. And the law of houses of walled cities is also explained in Scripture, and I have already written it later as well.