How to Find Comparable Sales for Your Property Tax Appeal

Comparable sales—or "comps"—are the foundation of almost every successful property tax appeal. This guide shows you exactly how to find, evaluate, and present comparable sales to support your case for a lower property assessment.

Why Comparable Sales Matter

When you appeal your property tax assessment, you're essentially arguing that your property is worth less than the county believes. The most persuasive way to make this argument is with evidence of what similar properties actually sold for.

County assessors use comparable sales as part of their own valuation process, so presenting strong comps speaks their language. If you can show that properties similar to yours are selling for less than your assessed value, you have a compelling case.

What Makes a Good Comparable

Not all sales make good comparables. The assessor's office will scrutinize your comps, so it's important to select properties that truly support your case.

Key Factors for Comparable Selection

1. Location (Most Important)

• Same neighborhood or subdivision: Ideally within the same development
• Distance: Generally within 1 mile, closer is better
• Similar setting: Urban to urban, suburban to suburban, rural to rural
• School district: Same district if possible

2. Physical Characteristics

• Square footage: Within 10-20% of your home's size
• Lot size: Comparable acreage or lot dimensions
• Bedrooms/bathrooms: Same or similar count
• Style: Ranch to ranch, two-story to two-story, etc.
• Construction: Similar materials (brick, frame, etc.)

3. Age and Condition

• Year built: Within 10-15 years of your home
• Condition: Similar maintenance level and updates
• Renovations: Account for major updates or lack thereof

4. Sale Date and Type

• Recency: Within the past 6-12 months (more recent is better)
• Arms-length transaction: Normal market sale between unrelated parties
• NOT acceptable: Foreclosures, short sales, family transfers, estate sales below market

Where to Find Comparable Sales

You don't need expensive subscriptions to find good comparable sales. Here are the best free and low-cost resources:

Free Online Resources

County Assessor Websites

Your county assessor's website is often the best starting point. Most Tennessee counties provide online property search tools with sales history.

• Davidson County: padctn.org
• Williamson County: williamsoncounty-tn.gov/assessor

Real Estate Websites

• Zillow: Shows recent sales, sale prices, and property details. Use the "Recently Sold" filter.
• Redfin: Often has more accurate data and shows days on market.
• Realtor.com: Good for recently sold properties with photos.
• Trulia: Useful for neighborhood-level data.

Tennessee Comptroller

The Tennessee Comptroller's office maintains property assessment data that can be useful for research.

Paid Resources (Optional)

• MLS access: If you know a real estate agent, they may be able to pull detailed comps for you
• CoreLogic/Black Knight: Professional-grade data (expensive, typically used by appraisers)

Step-by-Step Research Process

Step 1: Start with Your Property

Before searching for comps, know your own property inside and out:

• Get your property record card from the assessor
• Verify square footage, lot size, year built, and features
• Note your current assessed value
• Identify any condition issues or negative factors

Step 2: Define Your Search Parameters

Set up your search criteria based on your property:

• Location: Start with your immediate neighborhood, expand if needed
• Size range: Your square footage ± 15-20%
• Date range: Past 6-12 months
• Property type: Same as yours (single-family, condo, etc.)

Step 3: Search Multiple Sources

Cast a wide net to find all potential comps:

1. Start with the county assessor's website for official sale records
2. Cross-reference with Zillow and Redfin for additional details and photos
3. Note the address, sale date, sale price, and key features of each potential comp

Step 4: Verify Each Sale

For each potential comparable, verify:

• Sale type: Was it an arms-length transaction?
• Condition at sale: Did it need work or was it updated?
• Days on market: A quick sale might indicate below-market pricing
• Any concessions: Did the seller pay closing costs or make repairs?

Step 5: Select Your Best 3-5 Comps

Quality matters more than quantity. Choose the comparables that:

• Most closely match your property
• Sold for less than your assessed value
• Are most recent
• Are easiest to defend if questioned

Presenting Your Comparables

How you present your comparables is almost as important as the comps themselves. A well-organized presentation shows professionalism and makes it easy for the assessor to understand your case.

Create a Comparison Grid

Organize your comps in a side-by-side comparison table:

Include Supporting Documentation

For each comparable, include:

• Property record card or listing details
• Photos (if available)
• Map showing proximity to your property
• Brief explanation of why this is a valid comparison

Write a Summary Statement

Include a brief narrative explaining your case:

"The attached comparable sales demonstrate that similar properties in my neighborhood have recently sold for $410,000 to $425,000. My property is currently assessed at $450,000, which is 6-10% higher than actual market transactions. I respectfully request that my assessed value be reduced to $420,000 to align with current market conditions."

Common Mistakes to Avoid

1. Using dissimilar properties: A 1,500 sq ft ranch isn't comparable to a 3,000 sq ft two-story, even if they're on the same street.
2. Including distressed sales: Foreclosures and short sales will be rejected immediately.
3. Using old sales: Sales from 2+ years ago carry little weight in a changing market.
4. Ignoring superior features: If a comp sold for less but has fewer bedrooms or no garage, acknowledge the difference.
5. Providing too many comps: 3-5 strong comparables beat 10 weak ones.
6. Not verifying data: Cross-check sale prices across multiple sources to ensure accuracy.
7. Cherry-picking: Don't ignore sales that undermine your case—address them proactively.

When to Get Professional Help

While you can certainly research comparables yourself, consider professional assistance if:

• Your property is unique: Custom homes, large acreage, or unusual properties require expertise to find appropriate comps
• Your time is valuable: Proper research can take 5-10+ hours
• Stakes are high: Higher-value properties mean bigger potential savings
• You're not finding good comps: Professionals have access to MLS data and know how to make adjustments
• You want the best chance of success: Experienced professionals know what works with assessors

With TN.tax's Full Service Appeal, we handle all the comparable research, analysis, and presentation. You pay nothing unless we successfully lower your assessment. Get a free evaluation to see if your property qualifies.