When are Condo association fees attached to the property?

Condominium unit ownership and assessments are not separate; assessments are always associated with a condominium unit.


LONGER ANSWER
Assessments connected to individual condominium units are included in the purchase/sale agreement, based on the allocated interest of that unit in a 100% total ownership of all the common areas in the community that are owned in common by all owners.

Said another way, one always buys/sells a condominium unit with assessments, the amount of each being determined annually by the association.

(Assessments pay bills to operate the community. Line items can include master insurance policy premium, maintenance and upkeep of amenities, contributions to reserves and other expenses to be funded by owners.)