Knut Unger is standing on a housing estate in Witten in the Ruhr area. "Parking for Vonovia tenants only" says the sign in front of him. Behind it are rows of residential buildings with stained window frames and run-down facades. Around Unger, advisor to the tenants' association in Witten, half a dozen tenants have come together for a tenants' meeting. The mood is excited.
The landlord of the apartments in the Witten district of Heven, the real estate group Vonovia from Bochum, has just given the tenants a kind of gift. A gift that nobody really likes.