Our guidance would be to follow the instructions given by the host institution and local officials.  If there isn’t a mandatory evacuation, we wouldn’t recommend insisting that all residents evacuate, as you might have some liability if they don’t have a safer place to go.  However, we don’t recommend that you require the House Director to stay if she wants to leave, in a recommended evacuation event, even if you have members staying.  The members are presumably adults and are able to make that decision. We recommend requiring something from each resident who stays in writing, such as an email, that they have elected to stay.