2025 Division Statistical Assistance

Time trending and performance evaluation analyses assistance is available through the Division for vacant land, residential improved, and commercial improved classes of real property. Counties requesting the Division’s assistance are advised to review this memorandum carefully. Please note that the Division’s assistance program is offered as a supplemental and complementary statistics review to the county’s internal work. This assistance is not intended to take the place of the county’s internal assessment statistics program.

To initiate the request for assistance, the county assessor must e-mail, fax, or mail an official “written request” for assistance to me. The “written request” for assistance must include information on the class(es) of property (vacant land, residential improved, and/or commercial improved) and type(s) of analysis(es) (time trending and/or performance evaluation analysis) requested. To speed up the process, it is recommended that you e-mail your request to me at joann.groff@state.co.us, and copy (cc) the request to Jennifer Earp, jennifer.earp@state.co.us.

Once approval has been granted, the county should submit the cleaned data set(s) with the qualified/verified sales information on a per class basis (separate file per class) in the format that is shown in this memorandum to Jennifer Earp via e-mail.

Remember to review this memorandum carefully before submitting your county data.

If you have any questions regarding this memorandum and/or the Division’s statistical assistance program, please contact Jennifer Earp at jennifer.earp@state.co.us or (303) 864-7766.

The requirements for this assistance are as follows:

• Written Request: A written request specifically identifying the class(es) of property (vacant land, residential improved, and/or commercial improved) and type(s) of analyses (time trending and/or performance evaluation analysis) requested must be submitted to the Property Tax Administrator (PTA).
• Proper Form: Data must be submitted in the proper electronic file type (Excel or SPSS) and form (appropriate variables, column headers), as detailed subsequently in this memorandum.
• Three Submissions Maximum: The Division will analyze a maximum of three separate submissions of data per property class per county. Each submission and/or resubmission of data in improper or inadequate form will count as one submission for the class.
• Deadline: No new requests for assistance will be accepted after March 7, 2025. No data analyses or re-analyses will be started after March 14, 2025.

County data files must be submitted in either Excel or SPSS electronic data files. If a data file is received in an inappropriate file (software files other than SPSS or Excel and/or combined classification files), difficult to use data format (non-conforming/misspelled column headings, etc.), and/or missing any of the required data needed to perform the county’s requested analysis; Division staff will contact the county to discuss what is needed to complete the statistical analysis. The county will then be required to resubmit a corrected data file.

Prior to submitting, review the following data requirements:

Each property classification (vacant land, residential, or commercial) must be submitted in a separate appropriately named file. Non-qualifying sales (ARL 3, Chapter 3, page 3.25) are to be coded out and excluded from the submitted sales list file.

Non-qualifying sales include but are not limited to the following:

• Multi-parcel sales
• Split or combined parcel sales
• Sales where classification has changed subsequent to the sale
• Sales that have had more than nominal changes since the date of sale

The county must make sure that there are no sale duplications in the data set. In addition, if there are any resales, only the most representative resale can be included in the data file for statistical analysis. Also note that the vacant land sales list must include the total actual value of each parcel, not any discounted values.

The following information and examples are provided to illustrate the required format (column headers and basic data/variables) for county submission.

Time Trending Assistance

In order for the Division staff to conduct time trend analyses, the county must submit the sales data in either an SPSS (.sav) or Excel (.xls) file. The sales data for the entire data-gathering period includes the following:

• ACCOUNT = Parcel identification number or schedule number
• ECAR = Economic area number
• USECD = Property use code (e.g. single-family residential = 1212)
• YOS = Year of sale (e.g. 2023)
• MOS = Month of sale (e.g. 10)
• ADJPRICE = Adjusted sales price
• LNDVAL = Total land value for the 2024 assessment year
• TOTVAL = Total actual value of the property for the 2024 assessment year (includes all outbuildings and extra features values)

Time Trending - Data Example

Performance Evaluation Analysis Assistance

In order to review the final 2025 values, submit the data in an SPSS (.sav) or Excel (.xls) format. The sales data should include the following:

• ACCOUNT = Parcel identification number or schedule number
• ECAR = Economic area number
• USECD = Property use code (e.g. single-family residential = 1212)
• YOS = Year of sale (e.g. 2023)
• MOS = Month of sale (e.g. 10)
• ADJPRICE = Adjusted sales price
• LNDVAL = Total land value for the 2025 assessment year
• TOTVAL = Total actual value of the property for the 2025 assessment year (includes all outbuildings and extra features values)

Valuation Performance Analysis - Data Example

Final 2025 values must be determined prior to submitting your data file for performance evaluation analysis. Sales lists should be attached to electronic mail addressed to jennifer.earp@state.co.us.  

Within 15 working days of receiving the clean data file in the appropriate format, our staff will work on the requested analysis and provide you with the related correspondences and/or feedback. Our assistance will conclude with a final written report to the county. For time trending analyses, we will indicate our opinion as to whether a time trend exists and the amount of trend per month. For performance evaluation analysis, the report will provide copies of reappraisal statistics by overall property class for each having 30 or more sales.

Remember that our statistical analysis is only as good as the data that we receive, so make sure that you send the “cleanest” data possible to the Division.

If you have any questions regarding this memorandum, please contact Jennifer Earp at jennifer.earp@state.co.us or (303) 864-7766.