Here are a few suggestions:
Book a bed at Kot Erasmus (which is a dormitory), Place des Paniers 1/101-108, LLN, koterasmus@gmail.com
You will be able to stay there 3 nights for 5 Euros/night, while looking for housing. Kot-Erasmus is a UCL student association.
You can book a room starting from August 26. Kot Erasmus opens on September 9. Arrival: before 16:00 unless you have informed them in advance of late arrival.
NOTE: Even if you don’t need to stay at Kot Erasmus, you are welcome to go their and meet with other exchange students and be informed of their different activities during the term.
Kot Ardoise: +32 10/454311 ; Place des Brabançons 2/301-309 ; kotardoise@kap.ucl.ac.be
Kot Oxfam: +32 10/452793 ; rue des Blancs Chevaux 4/001-010 ; kotoxfamlln@hotmail.com
Kot partenaire international: +32 10/459980 ; rue des Blancs Chevaux 32/001-009 ; kotpartenaires@hotmail.com
Different youth hostels in the country. The nearest of LLN would be in Brussels or Namur, but if you search for 'auberge de jeunesse' you should still find more of them!
IBIS Styles Hotel, Boulevard de Lauzelle, 61 – Tel. : +3210450911 – Cost : from 71€/night.
For accommodation at the UCL Housing Service, upon arrival go to rue de la Gare 6. You should go there and check regularly, as rooms will get available every day. Contact person: Mrs Laurence Mairesse.
Private owners and estate agents: see Accommodation
More information on accommodation in Louvain-la neuve for international students
We hope all this will help. Good luck!