Question:
According to Jewish law, what constitutes a synagogue? May one establish a synagogue in a private home, a store, etc.? How should one proclaim that a given structure is now a synagogue? -- Maya, Central Israel
Answer:
Any location that is suitable for prayer can be used as a synagogue.
In any event, for occasional use, there is no need to pronounce that the site in question is a synagogue. It is sufficient to declare that the place is a temporary prayer location.
In fact, the place can be a store, a residence, and even a gymnasium. As long as there is enough space for all the congregants and the room is arranged appropriately, the site can be used for prayer.
Best wishes.
(Rabbi Shmuel Slotki)