הלכה על מנחות 58:15

And [also] that which they said (Yoma 11b) that the mezuzah of an individual is to be checked twice in a seven-year period, and that of a group twice in a jubilee period. And [also] that which they said (Menachot 29b) concerning the crowns, "Rava [Rabbah] said, 'Seven letters in the mezuzah need three [letters,] zayin each, and these are them, shin, ayin, tet, nun, zayin, gimmel, tsaddi (shatnez gets)'" - meaning to say that each letter in the mezuzah from these requires three crowns. And [also] that which they said (Menachot 44a) that one who rents a house outside of the Land [of Israel] and one lives in an inn in the Land of Israel are exempt from a mezuzah for thirty days, but that one who rents a house in the Land of Israel is obligated immediately [to affix] a mezuzah. And [when a landlord] rents out a house to his fellow, it is upon the renter to bring a mezuzah and to affix it, as it is an obligation on the resident. And when he leaves, he can not take it [away] in his hand, unless the house belonged to a gentile (Mishneh Torah, Laws of Tefillin, Mezuzah and the Torah Scroll 5:11). And there are ten conditions that are required of a house before it is obligated in [having] a mezuzah, and these are them: 1)That there be enough [space] to make a square of four ells by four ells; 2) that it have two doorposts; 3) and a lintel; 4) and a roof; 5) and doors; 6) and that the gate be ten or more handbreadths tall; 7) that the house be non-sacred; 8) that it be designed for the residence of a man; 9) that it be designed for residing in dignity: 10) and that it be designed for permanent residence. And a house that has many openings is obligated in the affixing of a mezuzah in each of them, even though he is only accustomed to entering regularly through one of them (Menachot 44a; Mishneh Torah, Laws of Tefillin, Mezuzah and the Torah Scroll 6:10). And a small opening that is between a house and an attic that people sometimes make at the feet of a ladder, upon which people climb to the attic, is obligated in [having] a mezuzah. And rooms in a house - even a room within a room - are all obligated in [having] a mezuzah, since all of them are made for residing. [These] and the rest of the details of the commandment are [all] elucidated in the third chapter of Tractate Menachot (See Tur, Yoreh Deah 285).