My friend and I had a wonderful time staying at Helena's house. It is spotlessly clean and when we checked in, she took time to explain to us the area.
When we mentioned that we will be out late, Helena left the light on at the front door as the steps are quite dark during night time.
Transportation to the city centre is direct with the train, although I feel the station is a bit too far to walk to. On the last day, I took the bus as the bus stop is much closer than the train station. Taxi to Tegel airport costs €23.
Despite the freezing weather, the house is well insulated and we feel pretty warm inside the building.
I would recommend this place to anyone for future trip.