IE 11 Not Supported

For optimal browsing, we recommend Chrome, Firefox or Safari browsers.

Cook County, Ill., Opens Access to Residential Assessment Code

The Assessor’s Office published its assessment code and models, and officials say they fully expect to do the same for commercial properties in the future.

Illinois’ Cook County Assessor’s Office, which estimates the value of property within a jurisdiction that includes Chicago, has released its residential assessment code and models.

The move creates nigh-unprecedented transparency for a process that essentially determines how much residents must pay in property taxes. Perhaps most importantly, it marks a major step forward in open information practices, seeing as the only way to previously obtain such information was through Freedom of Information Act requests or a court order.

The information was first published this month at Chi Hack Night, a weekly Chicago-based civic tech meetup that ranks among the largest such gatherings in the nation.

Rob Ross, who is the chief data officer for the office, said this marks the first time an assessor’s office has done this in the U.S. And while Ross said it would be wonderful for the civic technology community to create new products or tools with the information, the rationale for making it public has more to do with transparency and accountability.

“If the public can look over your shoulder easily, it kind of lights a fire under [you],” Ross said. “You know if you make a mistake, it will be caught at some point. The public goes over this stuff with a fine-tooth comb.”

Making information like this public is a cornerstone of Cook County Assessor Fritz Kaegi’s office, Ross said, noting that they started work on the project shortly after taking office in December. On the technical end of things, the assessor's office published the code and data on the open source development platform GitHub, simultaneously making it available through the Cook County Open Data Portal.

In explaining why transparency and accountability are important for the assessor’s work, Ross noted that a mistake can result in a property being overtaxed by hundreds of dollars, which really adds up year to year. Now that the code is public, Ross said, a precedent has been set that can’t be reversed. It will become the standard of doing business in the city of Chicago.

To entrench the newly public code further, Ross said his office is working to create partnerships with local groups such as academic institutions, who could potentially use the code as part of student projects.

Another facet of this work would be creating a system with code related to commercial assessments that could be shared. Ross described the idea as “not that far off,” although not imminent. Whereas something like a house or condo is a durable asset that appreciates over time, commercial real estate must be appraised for its viability as an income stream, which makes its value more volatile, thereby layering extra factors that need to be considered. There are, however, project plans that will create a framework for this.

While no other major jurisdiction’s assessor’s office appears to have made such code public, this sort of transparency is on the rise throughout local government, for a number of different platforms. Most recently, New York City made public an API that its internal agencies and community groups can use to help direct residents to public benefits from local, state and federal government.

Associate editor for Government Technology magazine.