We strongly recommend the use of public transport.
By railway ("Deutsche Bahn") you arrive at Essen Hauptbahnhof (main station) then go by rapid transit system S 9 (direction: Wuppertal) to Velbert-Langenberg station (should take you about 20 minutes). From the station it's just a short walk (about 300 m) on the "Hauptstrasse" (turn left in front of the station). The street named Gröndelle branches on the right. Our office building is the second one on the left side.
If you arrive by car take Autobahn (highway) A 44 to exit Langenberg, then go to Velbert-Langenberg (ca 5 km). You will find sufficient free (as in "free drinks") parking space available in front of our office building.