926. A Window Between Courtyards

Eiruvin 3:1

Let’s say that there is a window in the wall that separates two courtyards. If the window is at least four handbreadths by four handbreadths (about 1’x1’) and within ten handbreadths of the ground (about 30”) the residents of the courtyards have the option to form a single eiruv. This option applies even if only a small portion of the window is within ten handbreadths of the ground. Joining together makes the two courtyards like a single courtyard, with carrying between them permitted. If the residents prefer, they may make two separate eiruvs. If they choose this option, then they may not carry between courtyards. If the window is smaller than four handbreadths by four handbreadths or if the entirety of the window is higher than ten handbreadths from the ground, then the residents may only make two separate eiruvs.

Eiruvin 3:2

The above restrictions only apply to a window between courtyards; when it comes to a window between two houses, the residents may make an eiruv together even if the window is entirely higher than ten handbreadths from the ground. Similarly, if there is a window between a house and a loft, the residents have the option to make a single eiruv even if there is no ladder to this window, so long as the window is four handbreadths by four handbreadths. If a square four handbreadths by four handbreadths can be circumscribed within a round window, it is treated like a square window.