Comparable sales — properties similar to yours that sold recently — are the most powerful evidence in a property tax appeal. This tutorial walks you through finding the best comps using free online tools.
What Makes a Good Comparable Sale?
A good comparable sale shares as many characteristics as possible with your property. The ideal comp is in the same neighborhood or subdivision, has similar square footage (within ±20%), was built within 10 years of your home, sold within the past 12 months, and is in similar condition.
| Factor | Ideal Range | Why It Matters |
|---|---|---|
| Location | Same subdivision or neighborhood | Location drives value more than any other factor |
| Sale date | Within 12 months of assessment date | Older sales may not reflect current market conditions |
| Square footage | ±20% of subject property | Size is the primary value driver after location |
| Year built | ±10 years | Age affects condition, systems, and buyer appeal |
| Condition | Similar or worse | Better-condition comps must be adjusted down |
| Bedrooms/baths | Same or similar count | Each additional bath adds $5,000–$15,000 in most markets |
Using Zillow to Find Comps
Zillow's 'Recently Sold' filter is one of the easiest ways to find comparable sales. Navigate to your neighborhood on Zillow, click 'Sold' in the filter bar, and set the date range to the past 12 months. Filter by property type (single family, condo, etc.) and set a square footage range around your home's size.
- Go to Zillow.com and search your address.
- Click 'Recently Sold' or set the filter to 'Sold' homes.
- Set the date range to 'Last 12 months'.
- Filter by property type matching yours.
- Set square footage range to ±20% of your home.
- Review each result and note address, sale price, sale date, sq ft, beds/baths, and year built.
Zillow's Zestimate is NOT a comparable sale. It is an automated estimate that is often inaccurate. Use only actual sale prices from the 'Sold' section.
Using Redfin for More Accurate Data
Redfin often has more accurate and detailed sale data than Zillow because it pulls directly from MLS feeds. Use the same process: search your area, filter to sold homes, and set your criteria. Redfin also shows the original list price vs. sale price, which can indicate whether a sale was distressed (sold below list).
Using County Appraisal District / Assessor Records
County assessor websites are the most authoritative source for comparable sales because they contain the actual deed transfer data. Most county assessor websites have a property search function where you can search by address, neighborhood, or subdivision. Look for a 'Sales Search' or 'Recent Sales' feature.
In Texas, every county appraisal district (CAD) website has a sales search tool. Search by subdivision name to find all sales in your neighborhood for the past 12–24 months. This is the same data the ARB will use.
What to Exclude from Your Comps
- Foreclosure sales and bank-owned (REO) sales — these are distressed sales below market value
- Estate sales and probate sales — often sold below market for speed
- Sales between family members or related parties
- Sales with seller financing or unusual terms
- Sales that occurred during a market disruption (e.g., COVID lockdowns)
- Properties with significantly different lot sizes, views, or location characteristics
Building Your Comps Grid
Once you have 3–5 good comps, organize them in a table showing: address, sale date, sale price, square footage, price per sq ft, year built, bedrooms, bathrooms, and any notable differences from your property. Calculate the median sale price and price per square foot. These are your target values.
Use the Property Tax Edge Sales Comparables Analyzer to automatically organize and format your comps into a presentation-ready grid for your hearing.