Is it permissible to place copies of the Quran and play Quranic recitations in a room that was formerly a bathroom and has been converted into a dressing room after renovation?

Yes, it is permissible to bring the Mushaf into old bathrooms and play the Quran within them after their impurity has been removed, they have been purified, and converted into a changing room. This is because the prohibition was due to the impurity of the place and the exposure of private parts. Once these characteristics are removed, the ruling is also removed. Evidence for this is the purification of the ground of the Prophet's Mosque, which was previously a graveyard for polytheists, and the permissibility of converting churches into mosques after removing their rituals. Similarly, impure places can be purified for prayer therein, for the ruling revolves around its cause, existing when the cause exists and ceasing when it ceases.