can the OC ask the owners to return it to common property and remove the fence and outdoor furniture?
Court of Appeal says maintenance requires the owners corporation to restore to its original condition any common property which has been altered, replaced or destroyed (without proper authority): Krimbogiannis.
Not only can the OC ask it can do if need be.
There is a duty the owners corporation owes to remove the item and restore the common property to its original condition.