937. A Small Courtyard That Breaches to a Larger Courtyard

Eiruvin 3:23

If a well is situated in the middle of a path that is between the walls of two courtyards, then the residents of both courtyards may draw water from the well on Shabbos without having to make any structural extensions to the well. This is so even when the well is more than four handbreadths (about a foot) from each wall. This is because neither party impedes the other’s ability to lift something in the air (i.e., they don’t carry the water from the well, they merely lift it directly from the well into their domains).

Eiruvin 3:24

Let’s say that the wall of a small courtyard was entirely breached before Shabbos began, opening it completely to a larger courtyard. In such a case, the residents of the larger courtyard may make an eiruv for themselves and carry because sections of their wall remain on either side. The residents of the smaller courtyard, however, may not transfer objects between their houses and the courtyard until they make a single eiruv together with the residents of the larger courtyard. The general rule is that the residences in the larger courtyard are considered part of the smaller courtyard but those of the smaller courtyard are not considered part of the larger courtyard.