The Foundation of Success
Comparable sales (comps) are the backbone of any successful property tax appeal. Master this skill, and you'll have the power to challenge unfair assessments and save thousands in taxes.
If property tax appeals were a courtroom, comparable sales would be your star witnesses. They provide the objective evidence that proves your property's true value. But not all comps are created equal—choosing the right ones can make or break your case.
What Are Comparable Sales?
Comparable sales are recently sold properties that are similar to yours in size, age, condition, and location. Assessors and appraisers use these sales to estimate what your property would sell for in the current market.
Why Comps Matter
Comparable sales are the most persuasive evidence in property tax appeals because they represent real market transactions—what actual buyers paid for similar properties. This beats theoretical assessments every time.
The Golden Rules of Comp Selection
1. Timing
Ideal: Sales within the last 6-12 months
Acceptable: Up to 18 months in stable markets
Avoid: Sales older than 18 months
2. Location
Best: Same neighborhood (0.25 miles)
Good: Same school district (0.5 miles)
Limit: Similar area (1 mile maximum)
3. Size Match
Square Footage: Within 20% (+/- 200-400 sq ft)
Lot Size: Similar size and characteristics
Bedrooms/Baths: Exact match preferred
4. Condition & Age
Age: Within 10-15 years ideal
Condition: Similar level of updates
Style: Same or similar architectural style
Advanced Comp Selection Strategies
Pro Tips for Stronger Comps
- Look for "Arms Length" Sales: Avoid sales between family members, foreclosures, or distressed sales
- Check Sale Conditions: Verify sales were typical market transactions, not quick sales or investor purchases
- Verify MLS Data: Cross-check multiple sources to ensure accuracy of square footage and features
- Consider Market Trends: Adjust older sales for market appreciation or depreciation
- Document Everything: Keep detailed records of where you found each comp and why you selected it
Where to Find Comparable Sales
Best Data Sources
Free Sources
- • County assessor websites
- • Realtor.com (sold listings)
- • Zillow (limited data)
- • Public records databases
- • Local real estate agent help
Professional Sources
- • MLS access through agents
- • Professional appraisal services
- • FairTaxer's comp database
- • Title company records
- • Courthouse deed records
How to Analyze and Adjust Comps
Raw comparable sales data is just the starting point. You need to adjust for differences to make accurate comparisons.
Common Adjustments
Building Your Comp Analysis Table
| Property | Sale Date | Sale Price | Sq Ft | $/Sq Ft | Adjustments | Adjusted Value |
|---|---|---|---|---|---|---|
| Your Property | - | ? | 1,650 | ? | - | ? |
| 123 Oak St | Mar 2024 | $245,000 | 1,580 | $155 | +$10,000 | $255,000 |
| 456 Elm Ave | Apr 2024 | $268,000 | 1,720 | $156 | -$15,000 | $253,000 |
| 789 Pine Dr | May 2024 | $259,000 | 1,640 | $158 | -$5,000 | $254,000 |
Analysis Result
Indicated Market Value: $254,000 (average of adjusted comps)
Current Assessment: $275,000
Potential Savings: $21,000 assessment reduction = ~$525 annual tax savings
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Common Mistakes to Avoid
Don't Do This
- • Using online estimates as comps
- • Selecting too many weak comps
- • Ignoring significant condition differences
- • Using foreclosure or distressed sales
- • Including properties too far away
- • Forgetting to adjust for time differences
Best Practices
- • Use 3-5 strong comps vs. 10+ weak ones
- • Verify all data independently
- • Document your adjustment reasoning
- • Focus on quality over quantity
- • Consider both higher and lower sales
- • Present data clearly and professionally
Presenting Your Comps Effectively
Professional Presentation Tips
- Create a Summary Table: Show key details of each comp at a glance
- Include Property Photos: Visual evidence of similarity
- Map the Locations: Show proximity to your property
- Explain Adjustments: Justify each adjustment with specific reasoning
- Provide Documentation: Include MLS sheets or sale records
- Calculate Conclusion: Clearly state your indicated value
Professional Comp Analysis by FairTaxer
Skip the hassle of hunting for comps and making complex adjustments. FairTaxer's AI automatically identifies the strongest comparable sales and performs professional-grade analysis to maximize your appeal success.
Real Success Story
Case Study: 3-Bedroom Ranch in Newton, MA
Challenge: Assessment jumped from $285,000 to $315,000 after reassessment
Strategy: Found 4 comparable sales ranging from $265,000-$285,000
Key Evidence: Properties sold 3-6 months prior, all within 0.3 miles
Result: Assessment reduced to $275,000, saving $1,000 annually
Strong comps made this appeal a slam dunk!
Your Next Steps
- Research recent sales in your immediate area
- Select 3-5 properties that best match yours
- Gather detailed information on each comp
- Make appropriate adjustments for differences
- Calculate your indicated market value
- Compare to your current assessment
- File your appeal if you find a significant difference
Master the art of comparable sales analysis, and you'll have the most powerful tool in property tax appeals. Remember: quality beats quantity every time.