Does the presence of a dog in one of the apartments prevent the angels from entering the entire building, or only the apartment where the dog is located, knowing that the dog is not for guarding?

If owning a dog is not for guarding, then it is forbidden. It is authentically narrated in a Hadith that angels do not enter a house in which there is a dog. Based on this, the presence of a dog in a specific apartment does not prevent angels from entering other apartments in the same building, because it is composed of several apartments and is not considered a single house. Thus, the punishment is restricted to the one who owns the dog in his apartment only.