An applicant for rental housing has a child who uses a wheelchair. The bathroom door in the dwelling unit is too narrow to permit the wheelchair to pass. The applicant asks the landlord for permission to widen the doorway at the applicant's own expense. It is unlawful for the landlord to refuse to permit the applicant to make the modification. Further, the landlord may not, in usual circumstances, condition permission for the modification on the applicant paying for the doorway to be narrowed at the end of the lease because a wider doorway will not interfere with the landlord's or the next tenant's use and enjoyment of the premises.