Two wards are standing above the fray stirred by Mayor Richard Daley's proposal to require developers who purchase discounted city land to set aside a certain amount for affordable housing.

In the Southwest Side's 25th Ward, there's a requirement that 21 percent of newly constructed homes and rental units be made available at below market rates, whether or not the land was discounted to developers by the city.

In the 26th Ward on the Northwest Side, developers are required to keep 30 percent of units built for home ownership affordable.

"Developers don't like it -- but they are willing to work with it," said Carolyn Dewitt, an aide to 25th Ward Alderman Daniel Solis. "That's the bottom line."

The requirements in both wards go beyond the mayor's proposal to expand the city's set aside policy, which involves developments of 10 units or more. The city only requires 10 percent of units be reserved for low-to moderate-income residents, 20 percent if city subsidies are involved.

The mayor recently proposed mandating set asides for all city land purchased for development and when a developer asks for certain zoning changes.

The 25th Ward has seen a boom in home ownership and, to a lesser degree, rental units, as formerly light industrial areas are being developed into housing units.

Rapid development in the Northwest Side neighborhood of Humboldt Park, which makes up most of the 26th Ward, has displaced thousands of lower-income residents in an area that has been marked by the conversion of rental units into homes and condos for sale, also out of reach of lower-income residents.

"You have to understand that you are not going to make as much money as you could in another community," said Luis Padial, director of development for 26th Ward Alderman Billy Ocasio. "We have a lot of need in this area. A lot of people want to have a home here."

In Chicago, almost 30 percent of more than a million Chicago households pay more than 35 percent of their income for housing. Also, more than 70 percent of extremely low-income households are similarly burdened, according to a study last year by the Voorhees Center for Neighborhood and Community Development at the University of Illinois at Chicago.