I am a cleaner and have worked in a building with disabled toilets BUT, on the particular floor where the toilets were situated it was open to the public so in that case there definately should be toilets open. And the building had disabled people working there so yes again. If there is no open to the public area or disabled workers i still think YES there should be toilets for the eventuality of people needing them. There are disabled who work and lots of disabled people around. Yes i think!.