The Cook County Assessor’s Office released a new public dataset containing building permits submitted to the office by municipalities. The data can be found on Cook County’s Open Data Portal. This release creates access to the data for all permits stored in iasWorld, the office’s system of record. Publishing the data allows users to search (for example, for a specific municipality), filter, sort, and download the data. More than half a million rows of permit data are included in the dataset. Permits list new construction and changes to a property that can change its assessed value and grow the tax base. The CCAO receives permits from municipalities and sorts them, determining whether the kind of work done on the property is likely to result in a new assessed value. If it is, a field inspection may take place. Permits are also used to administer the Home Improvement Exemption. When homeowners add an improvement to their home, they aren’t taxed on up to $75,000 of the added value for up to four years. The CCAO automatically applies this exemption after receiving a building permit and conducting a field check on the property. Over the last six years, the CCAO has hired more staff, implemented new technology, and improved our processes to better capture accurate data from permits. In addition to the release of this dataset, our office has made several other recent changes to eliminate bottlenecks and improve accuracy in our permit processing.