A mosque is not a condition for Jumu'a
Question
In a place where Jumu'a is fard, on a Friday some two to two and a half thousand listeners gathered for a sermon assembly. In the local mosque about fifty people prayed Jumu'a, and the rest of the people prayed the Jumu'a prayer, with its owner's permission, on a plot of farmland adjoining this settlement, on which there is at present no crop and around which stand the houses of the settlement. Now what requires an answer is this: was the Jumu'a prayer of the people there valid or not?
Answer
For Jumu'a it is a condition that [the place] be a city, a small town or a large village. A large village is one that, in its population and its needs such as a market and the like, is like a small town, and whose population count is at least three thousand. In a small village Jumu'a is not permissible. And in a settlement where Jumu'a is permissible, a congregational (jami')
Source: Fatawa Mahmudiyya
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