The poor slave Gwydion (Alexander) grew up in the house before defeating the wizard and leaving Llewdor. Later on, Derek Karlavaegen moved into the house. He did not find any trace of Manannan who had been transformed into a cat. Derek discovered the Eye Between the Worlds in the study, allowing him to contact the Other World. This building or a location in town maybe the location of the Llewdor College. Although it would seem that if it was the college, that Alexander would be the only 'enrollee' as Manannan almost never has guests.