From Brussels National Airport:
This train stops in :
From train station to Bel V office
Recommended : go to Brussels Central train station
Take metro line 5 (direction ERASME/ERASMUS) up to station BIZET. Take the escalator to leave the station and then cross the street (you can see that in the past there were tracks of a tram). Cross the Henri Deleers street at your right hand side (traffic lights) and follow this street to the left (down hill, 50 m) up to the first crossroads. Take the Robert Buyck street to the right and follow this street up to the T-junction. Then turn left (Resedas street). Follow this road to the next T-junction and turn right. This is the Walcourt street. The Bel V building is at about 200 meters at your left hand.
Total: about a 7-minute walk.
A litte bit more difficult : from Brussels Midi / Zuid station; ¼ h bus
Leave the station towards the bus and tram stations in “Overdekte Straat / Rue Couverte”) (do not go down towards the metrostation). Take bus N° 49 or bus N° 78; they both wait there till their departure time (for time schedules see www.mivb.be)