Time Trending Analysis

In the 2019 reappraisal, the Jefferson County Assessor's Office used Sales Ratio and Multiple Regression Analyses for the determination of market trends. Paired sales were not used due to the number of fix and flip scenarios which changed the inventory However, a major component influencing value were remodels to homes. For those scenarios, the most current sale was typically used for analysis. The two-year time frame (2017 to 2019) showed a continued upward trend for all residential properties. the total number of qualified sales was 23,430, a minimal increase from the 23,387 in 2017. 

There was little evidence of foreclosure on lender-owned sales. New homes were removed from the time trend analysis so that only properties used in the prior reappraisal were considered for the ratio study New home sales were included in the overall valuation analysis. Jeffco's vacant land availability is dwindling, which was reflected in the strong trend for vacant land sales and the increasing number of existing residential home demos. The analysis indicated different results by property subclasses and location. See the table below for specific adjustment time periods and amounts. Time trend total adjustments ranged from 9% to258% - and varied by property type and economic area.  

The Residential Time-Trend Study Graph (PDF) represents the 24-month time frame. The red line is the regression line and its “best fit” position. The blue line represents the median sales ratio for each month. July 2016 is Month 1; December 2016 is Month 6; June 2017 is Month 12; and June 2018 is Month 24.