I really enjoyed my one-month stay at Marcel's house. The house is located uphill right next to Park Guell. You can enjoy a fantastic view of the city if you go to the building's rooftop and it's located 30 min away from the Natural Park de Collserola. People who enjoy nature and long walks will be in the right place. The apartment is nicely decorated, in a very quiet building, and it has a very enjoyable greenhouse dining room, where you can appreciate the always sunny sky of Barcelona. Also, there is a bus stop in front of the building and you are 10 min away from the Vallcarca metro station.
Marcel is a very nice person, always happy to chat and very responsive when you ask him questions. I am very happy with my stay and won't hesitate to rent a room again in Marcel's house!