The owner of an apartment, who is at the same time joint owner of the property, must pay his/her share in all costs which arise in the use of the property.
Specifically, these are operating costs (sewage charge, costs for rubbish collection or property tax), administration costs, maintenance costs (costs for repairs of the outside of the building or necessary repairs) and expenditures for communal facilities (green areas, elevators).
Additionally, there are contributions for the reserve funds of the property, which are a provision for future expenditure and are paid into a separate account for exactly that purpose.