94:14 If a person is a guest in a courtyard (even if he's paying a rental fee - see Mishnah Brurah 370:13), some authorities say that even if he is staying in a house by himself, as long as he's not remaining permanently but only for thirty days or less, then he doesn't impede the residents of the courtyard. Everyone can therefore carry, both from the residents' houses and from the guest's house. This is true even if there are many guests and only one resident homeowner. For this to be the case, there must be at least one resident homeowner, even a non-Jew; then the guests are all subordinate to him. However, if all of them are guests and there is no resident homeowner, then the guests impede one another so long as each one has a room designated for eating.
If there is a non-Jew among them, they must rent his home as will be explained in the next halacha. Some authorities say that there is no difference between a guest and a homeowner: everyone who has a designated room to eat in is considered like a homeowner. It's appropriate to try to act stringently in this matter. In such a case, the eiruv should be made without reciting the bracha. After the fact, if one did not do so, we may rely on the first opinion.
94:15 If a Jew lives in the same courtyard as a non-Jew, the non-Jew does not impede him, so the Jew may carry from the house to the courtyard and vice versa. Even if there are two or more Jews, so long as they live in such a way that does not require them to make an eiruv as discussed in 94:13, then the non-Jew would also not impede them. However, if there are two or more Jews who would need to make an eiruv and there is also a non-Jew living there, then he does impede them. In such a case, the Jews cannot make an eiruv until they have rent the non-Jew's home from him. If there are two or more non-Jews living there, they must rent from each of them. (The rental should be made before the eiruv; if the eiruv is made first, the bracha is not recited - Bi'ur Halacha 382:1 s.v. tzarich.)