939. Residents of a Courtyard Who Dine at the Same Table

Eiruvin 4:2

Continuing the case of a courtyard whose residents all dine at the same table: If the residents of this courtyard need to make an eiruv with the residents of another courtyard, they need only bring one loaf to the place where the eiruv will be made. If the eiruv is made in their house, they do not have to contribute to the eiruv, just as the house where an eiruv is placed need not contribute. The reason for this is that all the houses in this courtyard are considered like a single house.

Eiruvin 4:3

Similarly, if the residents of a courtyard made an eiruv together, they are considered like a single household. If they need to make an eiruv with the residents of another courtyard, they need only bring one loaf to the place where the eiruv will be made; if the eiruv is made in their house, they need not contribute to it.