From the train station:
Take tram no. 6, direction
St Peter Schulzentrum, and exit at stop
Neue Technik. Walk the
Steyrergasse uphill, and you find the physics building on the left side at the next crossing with a traffic light. You can enter either from Steyrergasse or from Petersgasse.
From the airport:
There are several options, taking a taxi is for sure the quickest and most convenient one. However, there is also public transport from the airport to town: if you take the train, you will end up at the main train station, and you have to follow the description above. If you take the bus, it will take you to
Jakominiplatz. From there, you can also take tram no. 6 as above. Fore more information about the transport from and to the airport, including timetables, you can visit the homepage of
Graz Airport.