If there's a condition in your rented co-op or condo apartment, or the building, that needs correcting and you haven't obtained satisfaction after several polite requests, you may then have to notify the owner of the unit (your landlord) in writing. The landlord is responsible for fixing defects or problems, whether it's a repair, difficulties with neighbors, or other adverse circumstances. Managing Agents, the Board of Directors, or the Condominium Board also deal with these issues, depending on the building's legal arrangements and the entity you rent from. There may even be two Managing Agents: one for the co-op or condo and another for the rental units. In addition to your landlord, notify the individuals serving in these capacities with a letter that describes the complaint concretely. If possible, state the cause of the condition. Request immediate action. By following these procedures, if you have to go to Housing Court to enforce your rights, you will be in a stronger position to get the repairs or relief you need.