20 ILCS 3805/8
The Authority may, pursuant to its rules or regulations, or pursuant to agreements with persons to whom it makes mortgage or other loans, provide for methods of limiting profits or cash flow or other distributions available to limited-profit entities to whom it has made or will make such loans. Such methods may include, without limitation, a limitation which may vary from period to period based on changes in the costs of borrowing money and may be changed from time to time. With respect to mortgage loans to limited profit entities, the alternative method shall be such as shall, in the sole judgment of the Authority, result in the lowest rents consistent with attracting private enterprise to acquire, construct, rehabilitate, operate and maintain the development. The equity in a development shall consist of the difference between the amount of the mortgage loan and the total cost of the development. The total cost of the development shall include construction or rehabilitation costs including job overhead and a builder's and sponsor's profit and risk fee, architectural, engineering, legal, and accounting costs, organizational expenses, land value, interest and financing charges paid during construction, and the cost of landscaping and off-site improvements, whether or not such costs have been paid in cash or in a form other than cash.
20 ILCS 3805/8