Neighborhood polygons used by the Cook County Assessor's Office for valuation and reporting. These neighborhoods are specific to the Assessor. They are intended to represent homogenous housing submarkets, NOT Chicago community areas or municipalities.

These neighborhoods were reconstructed from individual parcels using spatial buffering and simplification. The full transformation script can be found on the Assessor's GitHub.

Read about the Assessor's 2023 Open Data Refresh.

Residential condominium unit characteristics collected and maintained by the Assessor's office for all of Cook County, from 1999 to present. The office uses this data primarily for valuation, assessments, and reporting. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. This data is unit-level. Each 14-digit PIN represents one condominium unit. The first 10 digits of each PIN are the condominium building. Additional notes: The Assessor's Office has historically not tracked any internal, unit-level characteristics for condominiums, including square footage, number of bedrooms, etc. In 2021, the office began to manually compile unit-level data from a variety of sources. The ultimate intention is to gather basic data on all condominium units in the county. As such, unit square footage, building total square footage, and unit number of bedrooms are only available on a per-triad basis after 2021. Future data updates will add these features for other areas. Condominiums are assessed based on their percentage of ownership. See the link below for more information on how this process works. The percentage of ownership for all units in a building should sum to 1. However, this may not always be the case in this data, since it does not include commercial units. Condominium parcels can also be parking areas, storage units, or common areas. Identifying these units can be challenging, and they are not valued using mass appraisal. The Assessor's Office has an ongoing effort to clean up and identify these unit records. Current property class codes, their levels of assessment, and descriptions can be found on the Assessor's website. Note that class codes details can change across time. Data will be updated monthly. Depending on the time of year, some third-party and internal data will be missing for the most recent year. Assessments mailed this year represent values from last year, so this isn't an issue. By the time the Data Department models values for this year, those data will have populated. Rowcount and characteristics for the current year are only final once the Assessor has certified the assessment roll for all townships.For more information on how this data is used to estimate condominium unit values, see the Assessor's condominium modeling code on GitHub. Township codes can be found in the legend of this map. For more information on the sourcing of attached data and the preparation of this dataset, see the Assessor's Standard Operating Procedures for Open Data on GitHub. Read about the Assessor's 2025 Open Data Refresh.

ZIP Code boundaries in Chicago. This dataset is in a format for spatial datasets that is inherently tabular but allows for a map as a derived view. Please click the indicated link below for such a map. To export the data in either tabular or geographic format, please use the Export button on this dataset.

Preference boundaries for selected charter schools in the Chicago Public Schools district. As opposed to elementary or high school attendance boundaries wherein each residing student is entitled to attend, charter boundaries simply serve as a guide for charter school administrators to use during the application/lottery process. Applicants residing within a specific boundary are generally given preference over applicants residing outside of the boundary. To view or use these shapefiles, compression software, such as 7-Zip, and special GIS software, such as ESRI ArcGIS or QGIS, are required. To download this file, right-click the 'Download 'link above and choose 'Save link as. '

Historic land, building, and total assessed values for all Cook County parcels appealed with the Board of Review, from 2010 to present. The Board of Review uses these values for reporting, evaluating assessment performance over time, and research.

When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded

This data is parcel-level. Each row contains the assessed values for a single PIN for a single year. Important notes: • Assessed values are available when the Board of Review closes appeals and certifies the values. • The values in this data are assessed values, NOT market values. Assessed values must be adjusted by their level of assessment (https://prodassets.cookcountyassessor.com/s3fs-public/form_documents/classcode.pdf) to arrive at market value. Note that levels of assessment may have changed throughout the time period covered by this data set. • This data set will be updated when each township is certified. However, note that there may be discrepancies between the Board of Review’s data and the Assessor's site and this data set, as each pull from a slightly different system. • Current property class codes, their levels of assessment, and descriptions can be found on the Assessor's website (https://prodassets.cookcountyassessor.com/s3fs-public/form_documents/classcode.pdf). Note that class codes details can change across time. • The Change Reason and No Change Reason fields are only populated starting with the 2015 year data.

All data provided here is prepared for internal purposes by the County of Cook only is provided to the public as a courtesy.

While efforts have been made to be as accurate as possible, Cook County provides the data for personal use “as is”. The data is not guaranteed to be accurate, correct, or complete. Information provided should not be used as a substitute for legal, business, tax, or other professional advice. The recipient/viewer should contact appropriate regulating agencies to determine accuracy or suitability of the data for a particular use. This data may not be used in states that do not allow the exclusion or limitation of incidental or consequential damages.

Cook County or its staff assume no liability whatsoever for any losses that might occur from the use, misuse, or inability to use its geospatial data, maps or websites. All materials appearing on a map, geospatial data or County web site are transmitted without warranty of any kind and are subject to the terms on this disclaimer.

Sidewalks in Chicago. To view or use these shapefiles, compression software, such as 7-Zip, and special GIS software, such as ESRI ArcGIS or QGIS, are required. To download this file, right-click the "Download" link above and choose "Save link as." Once unzipped, the .dbf file may be opened in any spreadsheet program, such as Microsoft Excel, and identifies the address associated with each sidewalk polygon where possible. Note this is a draft file and may be updated periodically.

This zip code layer was constructed by Nevada County GIS from voter registration rolls and Assessor Mailing Addresses. It is the best available data, but boundaries are not precise. Zip Codes 95712 (Chicago Park) and 95924 (Cedar Ridge) are for the US Post Office and PO boxes only. In Truckee, there is a 96160 Zip Code that is for PO Boxes only. This zip code is not included in this layer because the Truckee Post Office itself is zip 96161.

Attendance boundaries for elementary schools in the Chicago Public Schools district for school year 2014-2015. Generally, all students in the applicable elementary school grades who live within one of these boundaries may attend the school. To view or use these shapefiles, compression software, such as 7-Zip, and special GIS software, such as Google Earth or ArcGIS, are required.

A dataset showing the population of 60618 between 2010 and 2020.

This is a Cook County Feature class of Unincorporated Zoning District Boundaries (Aggregate). This data is provided by the Cook County Dept. Of Building and Zoning and is maintained by the Cook County Zoning Board of Appeals. Only unincorporated district boundaries are available, please contact specific municipalities for questions regarding incorporated municipal zoning districts.

District-run elementary schools in CPS are organized into 13 Geographic Networks, which provide administrative support, strategic direction, and leadership development to the schools within each Network.

​​​​​This dataset is in a forma​​t for spatial datasets that is inherently tabular but allows for a map as a derived view. Please click the indicated link below for such a map.

To export the data in either tabular or geographic format, please use the Export button on this dataset.