@Parley thanks, But the link doesn't clarify the doubt that I have. it says -
While in self-quarantine, you must not share bedrooms, bathrooms or any other facilities with any other person who is not self-quarantining (for example, people outside your travelling party).
Does it mean they can still live with us on 1st floor and we can live on ground floor (in a double storey house) without need to do a self-quarantine?