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@ccao-data

Cook County Assessor's Office

The CCAO's Data Department creates models, tools, and analyses to improve Cook County's property tax system
README.md

Hi there! 👋

We're the Cook County Assessor's Data Department. We make predictive models to help determine the assessed value of every residential and condominium property in Cook County. We also make tools and reports to make the Cook County property system more transparent, predictable, and fair.

Our work

Our tiny team has done some big work since 2018. Here are some of the things we're most proud of:

Get involved

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  1. model-res-avm model-res-avm Public

    Automated valuation model for all class 200 residential properties in Cook County (except vacant land and condos)

    R 52 12

  2. data-architecture data-architecture Public

    Codebase for CCAO data infrastructure construction and management

    R 11 4

  3. model-condo-avm model-condo-avm Public

    Automated valuation model for all class 299 and 399 residential condominiums in Cook County

    R 12 4

  4. ptaxsim ptaxsim Public

    R package for estimating Cook County property tax bills

    R 20 6

  5. model-sales-val model-sales-val Public

    Heuristics for detecting outlier and non-arms-length sales

    Python 2 1

  6. wiki wiki Public

    Handbook, how-tos, and other documentation

    HTML 6 2

Repositories

Showing 10 of 29 repositories
  • extract-permits Public

    Script and workflow for permit data extraction

    ccao-data/extract-permits’s past year of commit activity
    Python 0 0 2 1 Updated Oct 29, 2025
  • homeval Public

    Experimental report that shows the characteristics and the most significant sales that the CCAO's residential model used to value your home

    ccao-data/homeval’s past year of commit activity
    HTML 1 0 15 1 Updated Oct 29, 2025
  • model-res-avm Public

    Automated valuation model for all class 200 residential properties in Cook County (except vacant land and condos)

    ccao-data/model-res-avm’s past year of commit activity
    R 52 AGPL-3.0 12 30 7 Updated Oct 29, 2025
  • data-architecture Public

    Codebase for CCAO data infrastructure construction and management

    ccao-data/data-architecture’s past year of commit activity
    R 11 4 73 4 Updated Oct 29, 2025
  • recurring-data-requests Public

    Scripts that we maintain to fulfill common data requests

    ccao-data/recurring-data-requests’s past year of commit activity
    R 0 0 0 0 Updated Oct 29, 2025
  • model-sales-val Public

    Heuristics for detecting outlier and non-arms-length sales

    ccao-data/model-sales-val’s past year of commit activity
    Python 2 MIT 1 18 2 Updated Oct 23, 2025
  • model-condo-avm Public

    Automated valuation model for all class 299 and 399 residential condominiums in Cook County

    ccao-data/model-condo-avm’s past year of commit activity
    R 12 AGPL-3.0 4 2 0 Updated Oct 22, 2025
  • ptaxsim Public

    R package for estimating Cook County property tax bills

    ccao-data/ptaxsim’s past year of commit activity
    R 20 AGPL-3.0 6 18 2 Updated Oct 21, 2025
  • lightsnip Public

    Hard fork of curso-r/treesnip specifically for CCAO LightGBM regressions

    ccao-data/lightsnip’s past year of commit activity
    R 2 AGPL-3.0 1 1 1 Updated Oct 10, 2025
  • wiki Public

    Handbook, how-tos, and other documentation

    ccao-data/wiki’s past year of commit activity
    HTML 6 2 12 0 Updated Sep 25, 2025
View all repositories