This is a new concept that has been introduced in Germany, it originally comes from the Netherlands.
The idea is pretty noble, especially for students who have ever had to try and find a hostel at the beginnning of the semester and all you get are regrets or the places are too expensive. Remember the story: WG Search: A Kenyan shares her experience? It can be a nightmare trying to find a place.
The idea here is to have either a single student or several students staying in a house for a while to preventing vandalism and theft either until the owner returns or the owner decides on a new function
for the building. It can be as luxurious has having to stay at a 700m2 with a swimming pool
and throwing the meanest house parties (house parties are not allowed) to living with several students at the Berlin Kinderkrankenhaus. The house sitters are also not allowed t have guests who stay longer than a week nor smoke in the buildings or drill holes into the walls.
The whole thing costs €180 a month. If you’re interested you can check it out at: http://de.cameloteurope.com/