From Berlin Brandenburg Airport (BER) to the apartment: 

(40 minutes) RE8 → S Ostkreuz, change to S42 → S+U Schönhauser Allee, walk 6 minutes to the apartment

(44 minutes) FEX → S Ostkreuz, change to S42 → S+U Schönhauser Allee, walk 6 minutes to the apartment

(55 minutes) S9 → S Treptower Park, change to S42 → S+U Schönhauser Allee, walk 6 minutes to the apartment

(57 minutes) S9 → S Treptower Park, change to S8 → S+U Schönhauser Allee, walk 6 minutes to the apartment

(70 minutes) S9 → S Hackescher Markt, change to M1 → Schönhauser Allee / Bornholmer Straße, walk 4 minutes to the apartment

From Berlin Central Station to the apartment:

(21 minutes) RE5 → S+U Gesundbrunnen, change to S41 → S+U Schönhauser Allee, walk 6 minutes to the apartment

(22 minutes) FEX → S+U Gesundbrunnen, change to S41 → S+U Schönhauser Allee, walk 6 minutes to the apartment

(25 minutes) U5 → S+U Alexanderplatz, change to U2 → S+U Schönhauser Allee, walk 6 minutes to the apartment

(27 minutes) Tram 12 → U Eberswalder Straße, change to M1 → Schönhauser Allee / Bornholmer Straße, walk 4 minutes to the apartment

(28 minutes) S7 → S Hackescher Markt, change to M1 → S+U Schönhauser Allee, walk 6 minutes to the apartment

From Berlin Central Bus Station (ZOB) to the apartment:

(35 minutes) Walk 12 minutes to S Messe Nord/ZOB, S41 → S+U Schönhauser Allee, walk 6 minutes to the apartment