Trier University has several housing facilities itself (in German, they are called “Wohnheim”). Please contact the International Student Office for further information. Furthermore, there are certain possibilities to find privately rented apartments via posters or via the internet. Popular homepages that display vacant housing options are :
http://www.wg-gesucht.de/
http://www.hunderttausend.de/annoncen#k=
http://volksfreund.immowelt.de/