in many places, especially Monsey, people put shuls in their basement because then they do not have to pay property taxes and can raise their neighbors taxes. Basement shuls also provide easy access because they are on every block and you need not go far, basement shuls are partially responsible for the poor state of health within orthodoxy. Commonly referred to as a shtiebl.


Also, the primary reason Orthodox Judaism has schismed itself into an infinite number of sects, if you disagree with your Rov just start a shul in your basement, and poof- you're a Posek and a Dayan and a Rov. If you want to be a Rosh Yeshiva or a Rosh Kollel, you need a reallybig basement.