Every apartment owner can in principle treat his part of the building in special ownership as he wishes, in particular inhabit, rent, lease or use it in any other way and exclude others from influence (§ 13 para. 1 WEG). In this case, the protection of ownership applies to a property in sole ownership. However, this right also entails obligations for the apartment owner, for example, to maintain the parts of the building that are in separate ownership and to use the parts of the jointly owned property only in such a way that none of the other apartment owners suffers any disadvantage beyond the non-binding level of disadvantage that would result from living together in an orderly manner (§ 14 No. 1 WEG).