How Guernsey County Increased Tax Revenue with Sketch Inspect

Guernsey County uncovered hidden value using EagleView's Sketch Inspect.

Background

Covering 528 square miles in southeastern Ohio, Guernsey County is home to approximately 40,000 parcels. Despite its size, the county operates with a small real estate assessment team, led by Deputy Auditor and Real Estate Office Manager, Amy Swigart, who has been with the auditor’s office for nearly three decades. With a team of just five full-time staff members, the department handles everything from real estate data requests to ensuring the accuracy of property assessments that fund critical services like schools, emergency response, and infrastructure. 

Challenge

Like many jurisdictions, Guernsey County faced significant challenges in maintaining up-to-date and accurate property assessments. The county’s small team struggled to keep track of property changes across thousands of parcels. When relying on third-party appraisal firms, issues arose due to limited local knowledge, resulting in buildings being missed, improperly sized, or even placed on the wrong parcels. This situation led to uncollected tax revenue, discrepancies in assessments, and an inequitable tax base, with some property owners unknowingly paying less than their fair share while others shouldered a disproportionate burden. The county needed a solution that could streamline the review process and ensure accuracy with minimal manual effort. 

Solution

To address these challenges, Guernsey County adopted EagleView’s Sketch Inspect tool, an innovative solution designed to improve the accuracy of property sketch data and assessments. Sketch Inspect works by comparing recent, high-resolution aerial imagery to existing property sketches within the county’s Computer-Assisted Mass Appraisal (CAMA) system. Using proprietary algorithms, the tool identifies discrepancies—such as unrecorded additions, demolitions, or structural modifications—that may have gone undetected during previous assessments or were not recorded in previous sketch updates. 

Through an intuitive interface, Sketch Inspect flags properties with potential discrepancies, categorizing them by type and severity to help assessors prioritize their efforts. With side-by-side comparisons of current and historical imagery, assessors can quickly verify changes and correct inaccuracies without needing to physically visit each property, making it an ideal solution for a small, resource-limited team. And a built-in work order screen makes it easy to assign and track follow-up actions. 

Sketch Inspect automatically identifies and categorizes discrepancies in CAMA sketch data. In this example, a parcel is seen as having both a major mismatched sketch as well as a missing sketch for a small structure, both of which contribute to missing tax revenue for the county.  
Impact

The results for Guernsey County were immediate and substantial. On the first day of using Sketch Inspect, the county’s assessment team discovered 31 unrecorded buildings, leading to a $3,154,200 increase in appraised property value and an additional $50,614 in tax revenue. To date, Guernsey County has uncovered sketch issues on over 800 parcels, and the county estimates that each hour spent reviewing Sketch Inspect results generates approximately $3,000 in new tax revenue. 

According to Amy Swigart, the benefits of Sketch Inspect were both surprising and impactful: “The program paid for itself within a couple of weeks. We were shocked by how much value we uncovered in such a short time.” The tool has enabled Guernsey County to ensure fair and equitable assessments across properties, providing the community with a more stable and accurate tax base. 

First day of use:  

  • 31 unrecorded buildings found 
  • $3,154,200 increase in appraised property value 
  • $50,614 in additional tax revenue 
  • $3,000 in new tax revenue for every hour spent reviewing results 

Looking forward, Guernsey County plans to incorporate Sketch Inspect in future revaluation cycles, further embedding technology into their assessment processes. The county’s experience with Sketch Inspect highlights the powerful role of technology in modernizing property assessments and enhancing revenue for local governments. 

Here a parcel is seen missing a sketch for what appears to be a pool house. Sketch Inspect automatically identifies and categorizes this discrepancy, allowing staff to create a work order to resolve the missing sketch and ensure the county is collecting fair taxable revenue for the parcel.  
EagleView Quote

The program paid for itself within a couple of weeks. We were shocked by how much value we uncovered in such a short time.

Amy Swigart

Deputy Auditor and Real Estate Office Manager

Guernsey County Auditor

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