Some additional information. The center was built in 1974 as an international education center for IBM Europe, Middle East and Africa. Later a new wing was added.
The rooms were rather basic. I assume they made one hotel room from two student rooms.
We considered the pace the nicest prison in Europe. It is located in a beautiful forest, with magnificent rhododendrons in the season, but it is pretty islolated, at a 30 min. drive from central Brussels, without public transport (perhaps the hotel has a shuttle now).