244.59. A municipality may, by by-law, provide that, where it has fixed a rate specific to the category of non-residential immovables, the debtor of the tax imposed on a unit of assessment belonging to the group provided for in section 244.31 is entitled, under certain conditions, to an abatement taking into account the fact that the unit or non-residential premises of the unit are vacant.
The amount of the abatement shall not exceed the difference obtained by subtracting from the amount of the tax that is payable under the rules provided for in subdivision 4 from the amount that would be payable if the basic rate were applied.
The abatement shall be granted to the debtor only if the average percentage of unoccupancy of the unit for the reference period exceeds 20 %.