No such requirement exists for men. A woman is told that only male applicants would be considered for a teaching at a boy's school. A man is refused accomodation because the Landlord prefers female tennants who, he says, are quieter and more responsible. These cases constitute sex discrimination. You have the right to take action if you believe that you have been treated unfairly.
Sex discrimination is against the law.
You may wish to talk about your concerns to the person or the organisation involved. Or you may seek help from a representative of your Union or an Advocacy Service. Alternatively, or failing a satisfactory response, get in touch with an Advisor at the Equal Opportunity Commission. Inform you of the complaint procedure. The service is confidential, impartial and free of charge.