New construction values are pro-rated the first year. "The owner of property on January 1 also shall be liable, on a proportionate basis, for the increased taxes occasioned by the construction of new or added buildings, structures or other improvements on the property from the date when the occupancy permit was issued or from the date the new or added improvement was inhabitable and fit for occupancy or for intended customary use to December 31 of that year."
The Chief County Assessment Officer equalizes property values and publishes changes around the first part of November
The Board of Review accepts appeals for 30 days following the publication of assessments
If a taxpayer filed an appeal with the Board of Review and is not satisfied with the decision, the taxpayer has 30 days from the date of the written notice to file an appeal with the Illinois Property Tax Appeal Board
The deadline for splitting a parcel or combining 2 or more parcels is September 30 each year