PINVAL (PIN Valuation)

Cook County Assessor's Office


Interactive web application that produces a customized valuation report for an individual real estate property.

check New check Scoping check Scoping QA check Staffing check In progress check Final QA done_all Completed
This project is completed

Background and Motivation

Taxpayer’s property tax bill is determined in part by the Cook County Assessor’s opinion of their market value - what the property could sell for, if it were to sell. Taxpayers have the right to know how that opinion was formed, but explaining the complex valuation methodology is often impossible. This application is designed to explain to taxpayers how our office arrived at their property’s value, and to convince them that the value is a fair and accurate value. In cases where our office has made a mistake, this application will help uncover, define, and correct that mistake.

Project Description

A web application built in R that allows a user to input a Property Identification Number and returns an interactive report on that property’s value.

Intended Impact

The property tax funds a large portion of local government. For property owners, it is a very large and visible tax payment. Taxpayers rightly want to know whether or not they are paying their ‘fair share’ of property taxes. That depends in part on whether the Assessor’s estimate of their property’s market value is accurate. Unfortunately, there is not currently a way to easily determine whether the Assessor’s estimate of value is accurate. This application solves that problem by allowing taxpayers to produce a report customized to their individual property.

Internal Stakeholders


Internal People Available During the Project

Chief Data Officer Rob Ross, Senior Data Scientist Dan Snow, Communications Director Nicole Jardine.

Start date: July 6, 2020
End date: Dec. 21, 2020

Project tasks

Project scoping 4 done_all
Project management 1 done_all
Task and project QA 1 done_all
Draft/Prototype of PINVAL 4 done_all
Implement and preview changes in stage 2 done_all
Project handoff 3 done_all