Cook_County_GISBuilding polygons across the 1,199 sq mi project area was captured through a semi-automated workflow using high-resolution lidar and ortho aerial imagery data collected in 2022. Automated algorithms first classified ground in the lidar point cloud and were reviewed for accuracy. After finalization of the ground classification, additional algorithms classified above ground features, such as buildings, vegetation, rails, etc. Building classified points were clustered and converted to polygon vectors across the project area. The polygons produced from the described automated process(es) are visually assessed for gross errors and/or significant misclassifications referencing the existing 2022 orthoimagery and County-provided source material (e.g., countywide parcel information). The only corrective action taken was the splitting of single large polygons into multiple polygon features by interpreting the intersection of the parcel information, or the capture of a missing feature (structure). Each building polygon was lastly assigned an elevation value based on the highest lidar point in the interior of its respective polygon. Elevation values were reviewed for accuracy. All building polygons have attributes including square footage, collection year of lidar and imagery, ground elevation, highest lidar point, and height above ground.ArcGIS DynamicMapLayerhttps://hub.arcgis.com/datasets/7c4f47a3b32944e58c5f18652880fc05_0engCook CentralPublicBuilding Footprints 2022 [Illinois--Cook County]Web servicesIllinois--Cook CountyIllinois2022