If you walk into an informal review or an ARB hearing with one piece of evidence, make it comparable sales. Appraisal districts value property based on sales data — so when you show them sales of similar homes that sold for less than your assessed value, you're speaking their language. A strong set of comps is the single most effective evidence in a Texas property tax protest.
What counts as a comparable sale?
A comparable sale (or “comp”) is a property that sold on the open market and is meaningfully similar to yours. Appraisers use four main factors:
- Location: Same neighborhood, street, or subdivision ideally. Never more than a mile or two away unless you have a good reason.
- Size: Similar square footage — within 15–20% of your home's living area.
- Age and condition: Built around the same era, similar renovation status. A renovated 2020 kitchen in a comp will make it sell higher than a dated one — adjust for that.
- Recency: Sold within the last 6–12 months. The closer to the appraisal date (January 1 of the tax year), the stronger the comp.
The more closely your comps match these factors, the harder it is for the appraiser to dismiss them.
Where to find comparable sales
1. Zillow and Redfin (fastest starting point)
Search your address on Zillow or Redfin, then scroll to the “Nearby recently sold homes” section. Filter by sold date (last 12 months) and similar square footage. These sites pull from MLS data and public records and are a good way to quickly identify candidate comps.
Limitation: Zillow's Zestimate is not a comp — it's an automated estimate. Only use actual closed sale prices.
2. HAR.com (MLS data for Texas)
HAR.com is the Houston Association of Realtors' public portal and covers the entire Texas MLS. You can search sold listings by address, filter by date, bedrooms, and square footage. It's more detailed than Zillow and includes days-on-market and price reductions.
3. TCAD / WCAD / HCAD property search
Each appraisal district has a public property search portal where you can look up the assessed value and sales history of any property in the county. This is useful for two reasons:
- You can verify that a comp actually sold (as opposed to being listed) and at what price.
- You can see how the district is valuing the comparable property. If your comp is assessed lower than yours despite being similar, that's also useful evidence for an unequal appraisal argument.
4. Ask a realtor
A licensed realtor with MLS access can pull a formal Comparative Market Analysis (CMA) in under an hour. Many will do it for free as a relationship-building exercise, especially if you might sell in the next few years. A realtor-prepared CMA carries extra weight with appraisers because it follows a recognized professional format.
How many comps do you need?
Three to five strong comps is the sweet spot. One comp is easy to dismiss — “that house had foundation issues.” Five similar sales all below your assessed value is much harder to argue against. For a formal ARB hearing in Travis County, you'll need 5 sets of your evidence package (one for each ARB member, one for the district rep, one for yourself).
How to present your comps
Don't just hand over a Zillow printout. Create a simple one-page summary showing:
- Your property: address, square footage, year built, assessed value
- Each comp: address, sold price, sold date, square footage, year built
- Price per square foot for each (sold price ÷ square footage)
- Your conclusion: “Based on these 4 sales, my property's market value is approximately $X, which is below the assessed value of $Y.”
Keep it simple and factual. Appraisers see hundreds of protests — a clear, organized presentation gets taken more seriously than a stack of loose printouts.
Need help pulling and formatting comps?
Our document preparation service has a certified realtor pull MLS comp data and format a professional evidence package for your county. See our document help service for details — available for Travis, Williamson, and Hays County.