For purposes of taxation, property value is estimated by analyzing sales data of similar properties in a neighborhood. Other methods for determining value include the Cost Approach and the Income Approach.
Assessed value is the taxable portion of the estimated market value of a parcel of property. Residential property in Cook County is assessed at 10% of its estimated market value.
For example, a property with an estimated market value of $200,000 would have an assessed value of $20,000 (200,000 x 10%).
The County Assessor mails out a Notice of Proposed Assessed Valuation to property owners when there is a change in assessment. Property assessments are reviewed by the County Assessor every three years in Cook County (2014 was a re-assessment year for property owners in Stickney Township; 2017 and 2020 will also be re-assessment years).
The Illinois Property Tax Code allows for all like property to be assessed equally, or uniformly.
One way to determine if your property assessment is uniform is by the price per square foot of the building. You can find this number by dividing the square footage of your building into the building value of your property assessment. (Condominiums are valuated using different criteria)
Consider the following example - a home with a living area of 1,200 square feet; a land assessed value of 5,000; a building assessed value of 20,000; and a total assessed value of 25,000.
We then have:
20,000 / 1,200 = 16.67 per square foot
Now we need to identify comparable properties. Comparable properties must have a lower total assessed value; they must be within your neighborhood; they must be the same classification; and they should be similar in style and structure to the subject property. Use the Cook County Assessor's website to identify comparable properties.