Ill. Admin. Code tit. 23, § 100.60 – Capital Assets and Depreciation

a) In order to account for capital assets properly, each school board shall adopt a capitalization threshold.
b) For purposes of calculating per capita costs under Section 18-3 of the School Code [105 ILCS 5/18-3], the depreciation allowance shall include both depreciable capital assets and non-capitalized equipment.

c) Unless otherwise required by state or federal law or regulation, useful lifetimes and annual depreciation rates for various classes of capital assets and non-capitalized equipment shall be based on the following schedule.

Classification	Estimated Useful Lifetime	Annual Depreciation Rate
Works of Art and Historical Treasures	Permanent	None
Land	Permanent	None
Permanent Buildings	50 Years	2%
Temporary Buildings	20 Years	5%
Improvements other than Buildings (Infrastructure)	20 Years	5%
Equipment (Three-Year Schedule)	3 Years	33⅓%
Equipment (Five-Year Schedule)	5 Years	20%
Equipment (Ten-Year Schedule)	10 Years	10%
Construction in Progress	Not Applicable	None
Non-Capitalized Equipment	10 Years	10%