RT-4A, Chicago zoning's epic fail.

With the 2004 re-write of the zoning code, the city fathers included a new classification. RT-4A, the "A" is for accessible.

Elevator buildings are largely accessible by design, but the bulk of the housing out in the neighborhoods isn't. Mostly, it's historic stock that is nearly impossible to retrofit.

They came up with a noble, almost ingenious plan. In RT-4 neighborhoods, neighborhoods designed for three flats and six flats, if you made 1/3 of your units ADA accessible you would get a bonus in floor area. The floor area ratio would go from 1.2 for RT-4 to 1.5 for RT-4A,

Sounds like a no brainer. All you have to do is build the ground floor of your three flat at ground level, make moderate changes to door widths and fixtures, and Bob's yer uncle. No need for elevators, or extensive ramps. These accessible units would just blend into the streetscape.

One would expect that it would become the standard for infill construction.

However, reviewing the city's zoning data (compiled to 2014) I find only about 50-60 lots in the city zoned to RT-4A. What's is worse, almost none of these were built. As far as I can tell, only 3 projects with a total of 5 accessible units have been built. More than 10 years after the introduction of this classification.

Why hasn't this worked? The folks downtown failed to do the math.

If you look around a residential neighborhood in Chicago, you will notice a consistent pattern. The first floor is four or five feet above the sidewalk. This isn't done for privacy or flooding concerns, this is done because of zoning. The zoning code doesn't consider most basements to count toward the floor area of the building. But from the builders' standpoint, a finished basement is saleable square footage.

To take advantage of this, the developer of a RT-4 three flat, will build 3 1/2 stories tall. Three floors of .4 FAR each that make up his 1.2 zoning FAR and a finished basement. That makes a total saleable FAR of 1.6. If he builds to RT-4A, with a ground level first floor, he loses the basement and only gets a total of 1.5 FAR.

The bonus for accessible has to go to .4 FAR just to break even and should probably go to .5 to create an incentive.