Altering a Shul Structure’s Layout
The space of a shul is sacred, which is why it is forbidden to reduce that area in any way. This includes dismantling any part of a shul, even an internal wall. Doing so would only be permissible l’tzorech binyan, for the purpose of ultimately expanding or beautifying the shul, and if the tikkun (improvement) takes effect in the same spot of the temporary hashchasah (demolition) and will maintain the same level of kedushah (holiness).
Based on this principle, the Tzemach Tzedek forbade the demolition of a wall separating the men’s and women’s sections and replacing it with a curtain, an act which was intended to increase the space in the latter area, because the loss to (the wall of) the main sanctuary of the shul (where davening and krias hatorah take place) would remain permanent and the gain would take place in a different place of lesser sanctity. However, he did permit shrinking the wall a bit if there was a great need. #481
פרטי הדברים ע״פ ד׳ הרמ״א או״ח סוסי׳ קנב. ט״ז סקנ״א סק״ג. א״ר שם סק״ז. ודנו בזה הפוסקים מכמה צדדים. ודעת אדמו״ר הצ״צ - בשו״ת הצ״צ או״ח ס״כ (הובא ונת׳ בלקו״ש חכ״ט ע׳ 12 ואילך בהערות).
והדעות בזה, הכל כאשר לכל, כשמלה פרושה - ראה באורך בס׳ משנת יוסף הלכות בית הכנסת (ליברמאן). הנסמן באנציקלופדיא תלמודית ערך לא תעשון. וזיל קרי בי רב.