A:
If the situation is as you have mentioned and the places assigned for Wudu', lavatories and so on are built under the minarets or close to the Masjid, there is no harm in it as long as it does not cause people or the Masjid any harm. There is no legal evidence prohibiting this.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.