For a 'different' meeting, we can suggest you the famous Brussels Royal Yacht Club.  All facilities are at your disposal : big parking space, 3 meeting rooms, a charming bar and a good restaurant with terrace.   

After the meeting you can have a boat trip on the Canal of Willebroek.  In this way you show your participants a piece of the industrial history and the new developments in the modern harbour of Brussels.  Lunch can also be taken onboard. 

As an alternative your meeting can be combined with a meeting onboard.