Assessor - Residential Condominium Unit Characteristics

Residential condominium unit characteristics collected and maintained by the Assessor's office for all of Cook County, from 1999 to present. The office uses this data primarily for valuation, assessments, and reporting.

When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded.

This data is unit-level. Each 14-digit PIN represents one condominium unit. The first 10 digits of each PIN are the condominium building. Additional notes: <ul><li>The Assessor's Office has historically not tracked any internal, unit-level characteristics for condominiums, including square footage, number of bedrooms, etc. In 2021, the office began to manually compile unit-level data from a variety of sources. The ultimate intention is to gather basic data on all condominium units in the county.</li>
<li>As such, unit square footage, building total square footage, and unit number of bedrooms are only available on a per-triad basis after 2021. Future data updates will add these features for other areas.</li>
<li>Condominiums are assessed based on their percentage of ownership. See the link below for more information on how this process works. The percentage of ownership for all units in a building should sum to 1. However, this may not always be the case in this data, since it does not include commercial units.</li>
<li>Condominium parcels can also be parking areas, storage units, or common areas. Identifying these units can be challenging, and they are not valued using mass appraisal. The Assessor's Office has an ongoing effort to clean up and identify these unit records.</li>
<li>Current property class codes, their levels of assessment, and descriptions can be found <a href="https://prodassets.cookcountyassessor.com/s3fs-public/form_documents/classcode.pdf">on the Assessor's website</a>. Note that class codes details can change across time.</li>
<li>Data will be updated bi-weekly.</li>
<li>Depending on the time of year, some third-party and internal data will be missing for the most recent year. Assessments mailed this year represent values from last year, so this isn't an issue. By the time the Data Department models values for this year, those data will have populated.</li>
<li>Rowcount and characteristics for the current year are only final once the Assessor <a href="https://www.cookcountyassessor.com/assessment-calendar-and-deadlines">has certified the assessment roll</a> for all townships.</li></ul>For more information on how this data is used to estimate condominium unit values, see the <a href="https://github.com/ccao-data/model-condo-avm">Assessor's condominium modeling code</a> on GitHub.

Township codes can be found <a href="https://prodassets.cookcountyassessor.com/s3fs-public/page_comm/trimap.pdf">in the legend of this map</a>.

For more information on the sourcing of attached data and the preparation of this dataset, see the <a href="https://github.com/ccao-data/wiki/blob/master/SOPs/Open-Data.md">Assessor's Standard Operating Procedures for Open Data</a> on GitHub.

<a href="https://datacatalog.cookcountyil.gov/stories/s/9bqn-cfsv">Read about the Assessor's 2023 Open Data Refresh.</a>

由评估办公室收集并维护的库克县住宅公寓单元特征数据，时间跨度从1999年至今。该办公室主要利用这些数据用于估值、评估和报告。

在处理地块索引编号（PIN）时，请确保将其填充至14位数字。一些数据集在下载时可能会丢失PIN的前导零。

本数据集为单元级数据。每个14位数字的PIN代表一个公寓单元。PIN的前10位数字代表公寓楼。以下为额外说明：

<ul>
<li>评估办公室历史上并未跟踪公寓的任何内部单元级特征，包括面积、卧室数量等。2021年起，办公室开始从各种来源手动收集单元级数据。最终目的是收集县内所有公寓单元的基本数据。</li>
<li>因此，单元面积、建筑总面积和单元卧室数量仅在2021年之后按三联单位提供。未来数据更新将为其他地区添加这些功能。</li>
<li>公寓的评估基于其所有权比例。有关此流程的更多信息，请参阅以下链接。建筑物中所有单元的所有权比例之和应等于1。然而，由于本数据集不包括商业单元，这可能并不总是成立。</li>
<li>公寓地块也可能包括停车区、储藏室或公共区域。识别这些单元可能具有挑战性，并且它们不使用批量评估。评估办公室正在努力清理和识别这些单元记录。</li>
<li>当前财产类别代码、评估级别及其描述可在评估办公室网站上找到。<a href="https://prodassets.cookcountyassessor.com/s3fs-public/form_documents/classcode.pdf">点击此处查看</a>。请注意，类别代码的详细信息可能随时间而变化。</li>
<li>数据将每两周更新一次。</li>
<li>根据年份的不同，最近一年的某些第三方和内部数据可能缺失。今年邮寄的评估报告代表去年的价值，这不是问题。等到数据部门为今年建模价值时，那些数据将已填充。</li>
<li>当前年份的行数和特征只有在评估办公室<a href="https://www.cookcountyassessor.com/assessment-calendar-and-deadlines">认证所有镇的评估清册</a>后才是最终的。</li>
</ul>
有关如何使用这些数据估计公寓单元价值的信息，请参阅GitHub上的评估办公室公寓建模代码<a href="https://github.com/ccao-data/model-condo-avm">点击此处</a>。

在地图的图例中可以找到乡镇代码。<a href="https://prodassets.cookcountyassessor.com/s3fs-public/page_comm/trimap.pdf">点击此处</a>。

有关附加数据的来源和此数据集的准备工作，请参阅GitHub上的评估办公室开放数据标准操作程序<a href="https://github.com/ccao-data/wiki/blob/master/SOPs/Open-Data.md">点击此处</a>。

有关评估办公室2023年开放数据更新的更多信息，请参阅<a href="https://datacatalog.cookcountyil.gov/stories/s/9bqn-cfsv">点击此处</a>。