Argyll and Bute Council will bring the rise into force next April in a bid to bring unoccupied properties back into the housing market.
The double charge will also apply to properties which have only been empty for one year, if they are not being actively marketed for sale or rent.
In June council records showed that there were 1470 properties in Argyll and Bute which were classed as unoccupied. There are also almost 1000 more properties where the council has written to owners to check on home occupancy status because council tax bills are sent to a different address.
Councillor George Freeman, Argyll and Bute Council's lead councillor for housing, said: "Where the new double council tax charge is applied, the council will set aside this income to benefit local areas."