35 ILCS 200/10-245
Notwithstanding Section 1-55 and except in counties with a population of more than 200,000 that classify property for the purposes of taxation, to determine 33 and one-third percent of the fair cash value of any low-income housing project developed under the Section 515 program or that qualifies for the low-income housing tax credit under Section 42 of the Internal Revenue Code, in assessing the project, local assessment officers must consider the actual or probable net operating income attributable to the property , using a vacancy rate of not more than 5%, capitalized at normal market rates. The interest rate to be used in developing the normal market value capitalization rate shall be one that reflects the prevailing cost of cash for other types of commercial real estate in the geographic market in which the low-income housing project is located.
35 ILCS 200/10-245