Lazhar's place is a nice one to stay.
It is very quiet, located in a green area as mentioned and is really comfy and clean. Moreover, it is pretty close to Zurich's central train station.
Lazhar and his roomies are very nice and available, and make you feel very comfortable.
I plan on staying there next time I go to Zurich, and obviously I recommend Lazhar's place to all those who want to enjoy their stay in a quiet environment.