It is also possible to find housing independently, even though the housing situation in Helsinki Metropolitan area is challenging in the beginning of each semester. If you did not get housing from HOAS or you prefer finding housing on your own, you can browse through the following websites. On the list you find links to different organisations which offer housing in the Helsinki area.
www.vuokraovi.com (also in English)
Links to some organizations and bulletin boards are also available in Haaga-Helia International Student Handbook at www.haaga-helia.fi -> In English -> Studies -> International Student's Guide.
The location of the apartments can be found out easily by copying the address to Google Maps http://maps.google.com/maps?hl=en&tab=wl