Most residence hall options are single-sex by wing (2-3 wings per floor that share a lobby/common area). Most halls have one wing male and one wing female or a mix if there are three wings on that floor. In the traditional community-style bathrooms, students would not share the bathroom with those of the opposite sex.
Our traditional-private wings do have co-ed options (residents share 4-5 lockable bathrooms with the opposite sex), the room selection process will indicate that on the specific room. If nothing is listed on the room, it is considered single-sex bathroom use.