Cook County Assessor's Modeling Data

datacatalog.cookcountyil.gov | Last Updated 8 May 2019

Modeling dataset used by the Cook County Assessor in their Computer Assisted Mass Appraisal system used to assess residential properties in Northern Triennial Townships. This dataset contains property information for every residential PIN in the Northern Triennial Townships where class is within a specified list of classes. For disclaimers, see dataset narrative at https://datacatalog.cookcountyil.gov/stories/s/p2kt-hk36

Tags: property, taxation, cook county assessor

This dataset has the following 60 columns:

Column NameAPI Column NameData TypeDescriptionSample Values
PINpintextUnique Permanent Identification Number for each property. All PINs are 14 digits: 2 digits for area + 2 digits for sub area + 2 digits for block + 2 digits for parcel + 4 digits for the multicode
Property ClassclassnumberProperty class. For a list of property classes, see https://www.cookcountyassessor.com/assets/forms/classcode.pdf
Tax Yeartax_yearnumberTax year of sale. Tax year referrs to the year in which taxes due. Taxes are billed a year in arrears. If a sale ocurred in calendar year 2018, it will be in tax year 2019.
Neighborhood CodenbhdnumberNeighborhood code as assigned by the Assessment office. An interactive map is available at https://maps.cookcountyil.gov/cookviewer/
Land Square Feethd_sfnumberSquare feet of the land (not just the building) of the property. Note that land is divided into 'plots' and 'parcels' - this field applies to parcels, identified by PIN
Town Codetown_codenumberTownship code as assigned by the Assessment office. An interactive map is available at https://maps.cookcountyil.gov/cookviewer/
Type of Residencetype_resdnumberType of residence - 1 = one story, 2 = two-story, 3 = three-story or higher, 4 = split level, 5 = 1.5 story, 6 = 1.6 story, 7 = 1.7 story , 8 = 1.8 story , 9 = 1.9 story (Note: residences with 1.5 - 1.9 stories are one story and have partial livable attics and are classified based on the square footage of the attic compared to the first floor of the house. So, 1.5 story houses have an attic that is 50% of the area of the first floor, 1.6 story houses are 60%, 1.7 are 70%, etc. However, what is recorded on the field card differs from what is in the database. All 1.5 - 1.9 story houses are coded as 5)
ApartmentsaptsnumberNumber of apartments in the building - 2 = Two, 3 = Three, 4 = Four, 5 = Five, 6 = Six, 0 = None
Wall Materialext_wallnumberExterior wall material - 1=Wood, 2=Masonry, 3=Wood&Masonry, 4=Stucco
Roof Materialroof_cnstnumberRoof construction material. 1 = Shingle/Asphalt, 2 = Tar & Gravel, 3 = Slate, 4 = Shake, 5 = Tile, 6 = Other
RoomsroomsnumberNumber of rooms in the property (excluding baths). Not to be confused with bedrooms.
BedroomsbedsnumberNumber of bedrooms in the property, defined based on building squarefoot and the judgement of the person in the field.
BasementbsmtnumberBasement type - 1 = Full, 2 = Slab, 3 = Partial, 4 = Crawl
Basement Finishbsmt_finnumberBasement finish - 1 = Formal rec room; 2 = Apartment; 3 = Unfinished
Central HeatingheatnumberCentral heating type - 1 = Warm air, 2 = Hot water steam, 3 = Electric, 4 = Other
Other HeatingoheatnumberOther heating type - 1 = Floor furnace, 2 = Unit heater, 3 = Stove, 4 = Solar, 5 = none
Central AirairnumberIs central airconditioning present? - 1 = yes, 2 = no
FireplacesfrplnumberNumber of fireplaces, counted as the number of flues one can see from the outside of the building.
Attic Typeattic_typenumberType of attic - 1 = Full, 2 = partial, 3 = none
Attic Finishattic_fnshnumberFinish of attic - 1 = Living area, 2 = Apartment, 3 = unfinished
Half BathshbathnumberNumber of half baths, defined as bathrooms without a shower or bathtub.
Design Plantp_plannumberPlan of Design - 1 = architect, 2 = stock plan
Cathedral Ceilingtp_dsgnnumberCathedral Ceiling - 1 = yes, 2 = No. (Note: the column name comes from a variable that is no longer used, but the column name was not changed to reflect Cathedral Ceiling)
Construction Qualitycnst_qltynumberConstruction quality - 1 = Deluxe, 2 = Average, 3 = Poor (There is one 4 in this dataset, but no 3. In general, this column is not useful for analytical purposes)
RenovationrenovationnumberConstruction renovation - 1 = yes, 2= no
Site DesirabilitysitenumberSite desirability - 1 = Beneficial to Value, 2 = Not relevant to Value, 3 = Detracts from Value. This field lack sufficient variation to be useful for modeling.
Garage 1 Sizegar1_sizenumberGarage 1 size - 1 = 1 car, 2 = 1.5 car, 3 = 2 car, 4 = 2.5 cars, 5 = 3 cars, 6 = 3.5 cars, 7 = none, 8 = 4 cars
Garage 1 Materialgar1_cnstnumberGarage 1 construction - 1 = Frame, 2 = Masonry, 3= Frame/Masonry, 4 = Stucco
Garage 1 Attachmentgar1_attnumberIs Garage 1 attached? 1 = Yes, 2 = No
Garage 1 Areagar1_areanumberIs Garage 1 physically including within the building area? 1 = Yes, 2 = No. If yes, the garage area is subtracted from the building square feet calculation by the field agent.
Garage 2 Sizegar2_sizenumberGarage 2 size - 1 = 1 car, 2 = 1.5 car, 3 = 2 car, 4 = 2.5 cars, 5 = 3 cars, 6 = 3.5 cars, 7 = none, 8 = 4 cars
Garage 2 Materialgar2_cnstnumberGarage 2 construction - 1 = Frame, 2 = Masonry, 3= Frame/Masonry, 4 = Stucco
Garage 2 Attachmentgar2_attnumberIs Garage 2 attached? 1 = Yes, 2 = No
Garage 2 Areagar2_areanumberIs Garage 2 physically including within the building area? 1 = Yes, 2 = No. If yes, the garage area is subtracted from the building square feet calculation by the field agent.
PorchporchnumberEnclosed porch - 1 = Frame, 2 = Masonry, 3 = None
Other Improvementsot_imprnumberOther improvements - if not 0, they contain a code. The definitions of these codes are maintained by the field workers. Unfortunatly, the way this data is entered makes it impossible to distinguish between a 1 & 2 and a 12, making this field mostly useless.
Building Square Feetbldg_sfnumberBuilding square feet, as measured from the exterior of the property
Repair Conditionrepair_cndnumberState of Repair - 1 = Above average, 2 = Average, 3 = Below average
Multi Codemulti_codenumberVariable that indicates that more one building exists on the PIN. 2 = one building, 3 = two buildings, etc… through 7 = 6 buildings.
Number of Commercial UnitsncunumberNumber of commercial units (the vast majority are for properties with class 212).
Estimate (Land)est_landnumberBoard of Review final estimated market value of land from the prior tax year.
Estimate (Building)est_bldgnumberBoard of Review final estimated market value of building from the prior tax year.
Sale Datesale_datecalendar_dateDate of sale
Deed No.doc_notextDeed number for sale
Sale Pricesale_pricenumberSale price
Longitudecentroid_xtextLongitude coordinate of the property's location, as defined by the centroid of the parcel shape in GIS.
Latitudecentroid_ytextLatitude coordinate of the property's location, as defined by the centroid of the parcel shape in GIS.
Census TracttractcetextCensus tract identifier - full map available through the Census Bureau, https://www.census.gov/geo/maps-data/maps/2010ref/st17_tract.html
Total Building Square Feettotal_bldg_sfnumberThis field applies to condominium properties (299) only. It is the sum of interior square feet of all units in the building.
Multi Property Indicatormulti_indnumberIndicator for a property with multiple improvements on one PIN, e.g. a main house and a coach house. NOT to be confused with a property which was part of a multi-pin sale.
Property AddressaddrtextProperty street address, not the address of the taxpayer.
Modeling Groupmodeling_grouptextModeling group, as defined by the property class. Properties with class 200, 201, 241, 299 is defined as "NCHARS", short for "no characteristics", which are condos and vacant land classes. Properties with class 202, 203, 204, 205, 206, 207, 208, 209, 210, 235, 278, and 295 are "SF", short for "single-family." Properties with class 211 and 212 are "MF", short for "multi-family."
Full BathsfbathnumberNumber of full bathrooms, defined as having a bath or shower. If this value is missing, the default value is set to 1.
AgeagenumberAge of the property. If missing, this defaults to 10. This field is a combination of original age and effective age where original age refers to the oldest component of the building and effective age is a relative judgement due to renovations or other improvements. For instance, if a property is completely demolished and built up again, the age resets to 1. But if portions of the original structure are kept, it may be more complicated to determine the age.
Useuse_1numberUse of property - 1 = single family, 2 = multi-family
Number of Unitsn_unitsnumberFor condos, the number of units in a building
Percent Ownershipper_assnumberPercent of ownership of a condo building for a unit as defined by the condominium declaration. If missing, default is 1/n_units.
Condo Class Factorcondo_class_factornumberFactor variable for NCHARS modeling group. Divides properties into two: Properties with class 200, 201, and 241 are given condo class factor as 200. Properties with class 299 are given condo class factor as 299
Multi-Family Indicatormulti_family_indnumberFactor variable for MF modeling group. Properties with class 211 are given multi-family indicator as 211. Properties with class 212 are given multi-family indicator as 212.
Large Lotlarge_lotnumberLarge lot factor variable, where 1 acre of land (land square feet > 43559) is defined as a large lot. 1 = large lot, 0 = not a large lot.