This is how apartment owners set rules for voting

The answer from the WiWo Coach, Notary Melanie Falkner: Although the Home Ownership Act was extensively amended and reformed in December 2020, the legal rule for the distribution of votes for resolutions at owners’ meetings remains unchanged. To answer your question: the head tuning principle applies. This means that every owner has one vote, no matter how many apartments they own. This principle is intended to avoid a majority power held by individual apartment owners. Conversely, the right to vote should not be increased by the fact that there are several owners of an apartment, such as in the case of married couples. You only have one vote.