Is the husband considered unjust and sinful for not equally providing housing for his two wives, and is the second wife entitled to demand equality in housing, especially if he allocated a much larger residence for the first wife than for the second?

Scholars have differed on the permissibility of a husband singling out one of his wives with more than the obligatory maintenance and housing. The fatwa adopted by us is that this is permissible. However, it is preferable for the husband to equalize between them as much as possible to achieve justice.