I have a friend from South America who was part of this movement, and lived in a convent. She was abused, and when she tried to escape they gave her horse tranquilizers to keep her captive. Some time later, after she left that dangerous group, she came to Christ and is now married. I don’t have much respect for Opus Dei.
Nuns live in a convent. There are no Opus Dei monks or nuns, contrary to what Dan Brown might have you believe.
There are celibate members, called "numeraries," who may or may not live with other numeraries of the same sex. There are also non-celibate members, called "supernumeraries".
As you can probably tell, I have tremendous respect for Opus Dei.