The Homebuilders Association of Greater Chicago is suing the city over rules which go into effect in two months which would mandate the creation of affordable housing without adequate compensation for developers.

The lawsuit, filed last week, says the city of Chicago’s Affordable Requirements Ordinance is unconstitutional.

According to the Chicago Business story:

Under the current ordinance, any developer of 10 or more residential units must have 10 percent of its units meet affordable housing requirements or pay a fee of $100,000 per unit to have all of the units be rented at market rate. Most big developers have paid the fee, which is placed into a pool used to create affordable housing units elsewhere.

Developers are rankled about the new rules because they mandate 10 percent of units must fall into affordable housing guidelines, or they face having to pay a substantial fee. The city says the rules are necessary to create or preserve more than 40,000 housing units that would fall into the affordable category.