# Research the history & age of a property Being connected to so many data sources, Chicago Cityscape is a good place to learn the history of a Chicago property. The data is best if you're looking to learn about changes since the early 2000s, but we have pointers to older data as well, including imagery and Census records. You will need to use multiple data sources to corroborate a building's age; there is not a single, authoritative source in Cook County. This Knowledge Base article is for property owners, prospective buyers, and for people researching for general interest, and will describe various ways to use Property Report to research the history of any property in Chicago. Many of these avenues require a paid membership. ## Building age Chicago Cityscape has information about building age for some properties, from the Cook County Assessor. The accuracy is low and hard to verify. Building ages may be fully accurate, or accurate to within a few years. The information is also not always updated as new buildings replace old buildings. ### Find building age in Chicago Cityscape #### Newer buildings If the building was built between 2006 and the present, there will be a new construction permit. Look up an address's Property Report and use Building Permits Browser to locate new construction building permits at that address or very close by. The permit's issue date will indicate the date when construction could commence. #### Older buildings If the building is older than 2006, look for the age data by looking up a Property Report, selecting its PIN, and then scrolling to the "Property & Ownership info" section. The information – which usually only exists for buildings with 1-6 units – will appear under "Building & site info" and have a "Building age" label. ### Find building age elsewhere The Cook County Assessor has a website (launched in 2022) called "Datalets", which presents some of the same and some additional information that their main website doesn't have. 1. In the Property Report, within the "Property & Ownership info" section, look for the heading "Links to other databases". There will be a link to "Assessor: Datalets for this property". Select that link, which opens a new tab. 2. If the property has a commercial building, select the "Commercial Building" link in the list on the left. If there is a residential building, select the "Residential Building" link in the list on the left. 3. In the list of property attributes, look for "Year Built". If you still cannot find building age information there, and you believe the building was built prior to 1960, then check the fire insurance maps. Learn how in the "Finding old maps" section below. ## Building permits & violations Chicago Cityscape has building permits since 2006 and building violations since 2001. [Look up an address](http://chicagocityscape.com/address.php) to get its Property Report and click the appropriate buttons to load the building permits and building violations (these are in separate sections). If the address has any building permits or violations, then only the permits and violations at that address will load. Click "Nearby permits" and "Nearby violations" to show adjacent permits and violations. *See also: [[Building violations]]* ### Older permits If you want to find permits and violations before those years, use the City of Chicago's [Building Permit & Inspection Records](https://webapps1.chicago.gov/buildingrecords/) website, which has some data going back to the 1980s for many buildings. This data is limited and will include the permit number and a short description. To access more information about an individual permit, the property owner or their representative can submit a FOIA request to the Chicago Department of Buildings. The University of Illinois at Chicago (UIC) library has an [online building permits database](https://researchguides.uic.edu/CBP/home), as well, for permits issued in 1872-1954. ## Environmental permits & inspections Sifting through old and recent environmental permits and inspections can give a sense of the types of businesses that operated at a location. Look up an address and then click on "Environmental Snapshot". On that page, click the appropriate buttons to load the environmental permits, environmental inspections, and storage tanks (these are in separate sections). This level of research will require reading through many descriptions, some of which can be long. But you may uncover some helpful information, including whether there was a car repair shop, a gas station, or some other business that must comply with air quality or pollution control regulations. ## Current and old imagery and maps Chicago Cityscape incorporates historical aerial imagery (photographed from airplanes, not satellites) from the Cook County government, also in Property Report. New imagery is captured annually; the oldest year is 1998. Cook County also captures oblique imagery, photographed at an angle in four directions, annually from 2017 to 2022 (as of January 12, 2023). ### Current imagery #### Show top-down imagery 1. Look up an [Property Report](/address.php) in Cook County. 2. Underneath the map at the top of an Property Report, select the "Historical imagery" button (see *screenshot 1* below). 3. The most recent year will display first; click the radio button in the list in the map to show older years. The imagery cannot be downloaded but you can take a screenshot of it.  *Screenshot 1* #### Show oblique (angled) aerial imagery 1. Look up an [Property Report](/address.php) in Cook County. 2. Underneath the map at the top of an Property Report, select the "Map tools" button (see *screenshot 2.a.* below). 3. Then select the "Aerial imagery" button – a new browser tab will open. ![[propertyhistory_aerialimagery.png]] *Screenshot 2.a. showing the buttons to select* On this imagery map, you can rotate the view. The cardinal directions refer to the view you will be facing if you select it; a "north" view will position the camera to face north.  *Screenshot 2.b. An example of "oblique" aerial imagery.* ### Older imagery Older aerial imagery can be useful to establish how long a building has existed. In Chicago this is necessary to establish for several building permit and zoning applications (including ADUs, bulk and density waivers, and parking waivers). #### Aerial photos from 1970 to 1995 The Chicago Metropolitan Agency for Planning has the following years in its collection: 1970, 1975, 1980, 1985, 1990, and 1995. The photos were taken for CMAP's predecessor, the Northeastern Illinois Planning Commission. [Open the map browser to locate imagery](https://experience.arcgis.com/experience/f2515ce87d39455d8c6608a4b11b6520/page/CMAP-Data-Explorer/?). The map has an address search function so it's not necessary to determine the township (but Surrounding Places will tell you the township for a given Property Report). Tip: CMAP's imagery browser works best on a computer with a fast internet connection as each image is very large and comes in a ZIP file.  *Screenshot 3. Top-down aerial photo from 1995 centered on the South Loop.* #### Very old aerial photos The State of Illinois took aerial photos of the entire state in 1936-1938 and the black & white images are searchable in the [Illinois Historical Aerial Photography](https://prairie-research.maps.arcgis.com/apps/webappviewer/index.html?id=a251e0a92bd84f978e46a0b2f3b5a50f) database. ### Finding old maps #### "80 Acre" maps Property Report also has a locator to the City of Chicago's "80 Acre" maps catalog (see *screenshot 4* below), which are scanned plat map sheets and have some indication as to the history of parcels, streets, and alleys. Select the [[[Historical maps locators]] button in Property Report (within Zoning Assessment) which will load a map showing the rectangular outlines of the 80 Acres maps. Click on a rectangle and a preview of the 80 Acre map will appear. Click on the "PDF" link to open the scanned sheet for that rectangle.  *Screenshot 4. A screenshot of the 80 Acres section in a Property Report's historical maps locator.* #### Fire insurance maps In the Historical maps locators section (Zoning Assessment>Expanded Zoning Assessment) you'll also find a locator for Sanborn maps produced in the 1980s and hosted by the City of Chicago. In our locator, select the "Load Sanborn maps" button. On the map that appears select a rectangle and then select the "PDF" link to open the scanned sheet for that rectangle.  *Screenshot 5. Chicago Cityscape-created a simplified Sanborn map legend for residential uses.*  *Screenshot 6. Chicago Cityscape-created a simplified Sanborn map legend for other uses.* ##### Additional Sanborn map resources - Use the Chicago Public Library's [fire insurance maps database](http://fims-historicalinfo-com.chipublib.idm.oclc.org). The database includes maps from Sanborn and other insurance companies. This database, which includes Sanborn maps in color but not from the 1980s, is provided by a third-party vendor and requires a CPL account to access. - Sanborn maps in black & white are in a [different database](https://www.chipublib.org/chicago-sanborn-maps-index/), also provided by the Chicago Public Library (no CPL account required). - If you need help locating a particular Sanborn map or volume, [use ChicagoInMaps.com's visual guide](http://chicagoinmaps.com/LOCsanbornsguide.html). ## Landmarks & landmark districts Many properties in Chicago are in landmark districts, are landmarked individually, or were noted in the Chicago Historic Resources Survey (CHRS). Chicago Cityscape's Property Report will help you determine if the property you're researching is in a landmark district, has been designated as an individual landmark. 1. [Look up an address](http://chicagocityscape.com/address.php) and load its Property Report. 2. Scroll down to "Other Data", or click "Landmarks & historic resources" in the Table of Contents. 3. Click the "Load..." buttons in both the "Landmarks" and "Historic Resources Survey" sections. 4. Maps and data tables will load for each section and show overlapping and nearby buildings and districts. The "Landmarks" section will also show districts and buildings that are included in the National Register of Historic Places. ## Related articles - [[Historic status in Chicago|Determine historic status of a building in Chicago]] - [[Third-party maps|Third-party maps]] - [[Shopping for a home]] - [[Finding aerial photography]] ## Other resources - Most Property Report's property class histories go back to 2009. This could be useful to know when a vacant lot was improved. - Refer to the City of Chicago's [Your House Has a History](https://webapps1.chicago.gov/landmarksweb/static/pdf/Your_House_Has_A_History.pdf) brochure for information about additional ways to research a property in Chicago. - Learn how to use historic Census data to [find the number of dwelling units a property used to have](https://www.stevencanplan.com/2023/03/determining-dwelling-unit-count-at-an-address-using-1950-census-records/)