How I Use Comparable Sales to Win Property Tax Protests in the RGV

Comparable sales are the backbone of every property tax protest I file. When I walk into an ARB hearing, the panel wants to see hard data showing your property is overvalued. The best data? Recent sales of similar properties that sold for less than your assessed value. But finding the right comps is an art, and presenting them effectively is what separates winning protests from losing ones.

What Makes a Strong Comparable Sale

Not every sale is useful. I evaluate comps on four criteria, and I am looking for the tightest match possible on all four:

1. Location

This is the most critical factor, especially in the RGV where neighborhoods can change character within a few blocks.

• Best: Same subdivision or neighborhood, within half a mile
• Good: Adjacent neighborhood with similar characteristics, same school zone
• Weak: Different submarket, different school district, or more than 2 miles away

2. Size and Configuration

• Square footage within 10-15% of the subject property
• Same number of bedrooms (or within one)
• Same number of bathrooms (or within half)
• Comparable lot size and garage configuration

3. Age and Condition

• Built within 10-15 years of the subject property
• Similar level of updates and maintenance
• Comparable construction quality

4. Timing

• Sales within the past 12 months are strongest
• Sales within 18 months are acceptable with adjustments
• Anything over 2 years old is generally too dated

Where I Find Comps

I use multiple data sources to build the most complete picture:

• County appraisal district records: The same data the district uses, which gives it high credibility with the ARB. Search properties at HCAD or Cameron CAD.
• MLS data: The most detailed source, including days on market, listing history, and actual sale prices.
• County clerk deed records: For verifying sale prices and confirming arm's-length transactions.
• Our proprietary database: Years of RGV protest data that helps us identify patterns and opportunities.

How I Analyze and Present Comps

Raw data is not enough. The panel needs to see a clear, logical argument. Here is my standard presentation format:

The Comparison Chart

I create a side-by-side chart showing each comp against the subject property. Columns include address, sale date, square footage, sale price, and price per square foot. At the bottom, I show the subject property's assessed value and price per square foot, making the disparity immediately obvious.

Adjustments

No two properties are identical, so I make transparent adjustments:

• If a comp has fewer bedrooms, I adjust its value upward to account for the difference
• If a comp is newer or in better condition, I adjust downward
• Location differences get adjusted based on market data
• Pool adjustments in the RGV typically range from $18,000-$35,000 depending on size and condition
• Flood zone location can warrant a 5-10% downward adjustment
• I show all adjustments clearly so the panel can follow my reasoning

The Summary Argument

I always end with a clear statement: here are 4-5 similar properties that recently sold, here is the adjusted average price per square foot, and here is why the subject property should be valued at X instead of Y.

Common Mistakes That Kill Protests

• Using inappropriate comps: Properties from different submarkets, vastly different sizes, or non-arm's-length sales.
• Cherry-picking: Only showing the lowest sales while ignoring higher ones. The panel will notice and your credibility suffers.
• No adjustments: Presenting raw sales without accounting for differences between properties.
• Too few comps: One or two comps are not enough. You need a pattern that tells a consistent story.
• Poor presentation: Disorganized data, no visual aids, and failing to explain why your comps support a lower value.

When Comps Are Not Enough

Sometimes comparable sales alone will not win the case. In those situations, I supplement with:

• Property condition evidence: Photos and repair estimates for issues that reduce value
• Unequal appraisal data: Showing your assessment is higher than similar properties (not sales, but current assessments)
• Income analysis: For rental and commercial properties, actual income data versus the district's assumptions

The strongest protests combine multiple types of evidence. Comps set the foundation, and supporting evidence reinforces the argument.

Get Started on Your Own

Start by searching your county appraisal district's website for recent sales in your neighborhood. Compare the price per square foot of those sales to your assessed value per square foot. If your assessment is noticeably higher, you likely have a case worth pursuing.