How to Find Comparable Properties for a Texas Property Tax Protest
The strongest argument in a Texas residential property tax protest is unequal appraisal — that your appraised value exceeds the median of comparable properties. The argument is statutory (§41.43(b)(3)), defensible, and provable from public data. But the strength of the argument is entirely about the quality of the comparable set. This guide is the complete procedural walkthrough: where to pull comps, how to filter them, how to compute the median, and how to build the evidence packet you'll submit to the CAD.
- What counts as a comparable property in Texas
- Where to find comp data — your CAD portal
- Step 1: Open your CAD's property search
- Step 2: Note your subject property's key data
- Step 3: Filter the universe of properties
- Step 4: Capture the comparable set
- Step 5: Compute the median
- Step 6: Apply the median to your property
- Step 7: Build the evidence packet PDF
- CAD-by-CAD search interface notes
- Common pitfalls to avoid
- FAQ
What counts as a comparable property in Texas
Texas Tax Code §41.43(b)(3) refers to "a reasonable number of comparable properties appropriately adjusted." What makes a property "comparable" is not statutorily defined — it's developed through CAD practice and ARB precedent. The industry-accepted criteria for residential protests:
| Variable | Standard Filter | Why |
|---|---|---|
| Location | Same subdivision or immediate neighborhood | Property values are highly location-specific. Cross-neighborhood comparisons are easily attacked by the CAD. |
| Square footage | ±25% of subject | Per-square-foot normalization handles size differences within this range. Beyond ±25%, the comparison breaks down. |
| Year built | ±10 years of subject | Construction era influences appraisal models (depreciation, replacement cost). Wider on very-old or very-new properties where comp scarcity forces it. |
| Construction class | Same CAD construction class code | CADs assign class codes (e.g., "N95" for standard single-family, "N03" for builder-upgrade). Mixing classes weakens the comparison. |
| Property type | Same property type (single-family / townhome / condo) | Different types have different valuation patterns even within the same neighborhood. |
| Pool / amenities | Same major amenity profile, or documented adjustment | A pool, large garage, or major addition can shift value by $20k-$50k. Comparing pool to no-pool requires documented adjustment. |
Where to find comp data — your CAD portal
Every Texas county appraisal district publishes a free public property search. The CAD's own data is the authoritative source for §41.43(b)(3) comp arguments because the standard compares appraised values — which only the CAD assigns and publishes.
| County | CAD | Search URL |
|---|---|---|
| Collin | CCAD | collincad.org |
| Dallas | DCAD | dallascad.org |
| Tarrant | TAD | tad.org |
| Denton | Denton CAD | dentoncad.com |
| Harris | HCAD | hcad.org |
| Travis | TCAD | traviscad.org |
| Bexar | BCAD | bcad.org |
| Williamson | WCAD | wcad.org |
| Fort Bend | FBCAD | fbcad.org |
| Galveston | Galveston CAD | galvestoncad.org |
| Johnson | Johnson CAD | johnsoncad.com |
| Rockwall | Rockwall CAD | rockwallcad.com |
Step 1: Open your CAD's property search
Open your CAD's public property search
Go to your CAD's website. Find "Property Search" — every Texas CAD has one prominently on the home page. No login required for basic property search.
If you don't know which CAD to use, look at your Notice of Appraised Value — the CAD's name is at the top of the notice.
Step 2: Note your subject property's key data
Pull your subject property and record its data
Search for your property by address. Click into the detail view. Record these fields:
- Square footage (improvement / living area square footage, not lot size)
- Year built
- Subdivision name or neighborhood code
- Construction class code (sometimes shown as a code like "N95," "R03," etc.)
- Current appraised value (the value you'll be challenging)
- Current per-square-foot appraised value = appraised value ÷ square footage
- Major features: pool? attached garage size? unique additions?
This is your subject's profile. Every comp must be reasonable-and-comparable to this.
Step 3: Filter the universe of properties
Apply filters to narrow the candidate set
From your CAD's search interface, find a way to filter or browse properties in your immediate area. Methods vary:
- Subdivision search: if your CAD's search lets you query by subdivision name, this is the cleanest filter. Returns every property in your specific subdivision.
- Neighborhood code search: some CADs assign internal neighborhood codes that are tighter than subdivisions. Use if available.
- Geographic search / map view: some CADs offer interactive map views that let you select properties geographically. Useful when subdivision boundaries don't match real-world neighborhoods.
- Street-name search: last resort. Pull every property on your street and adjacent streets, then filter manually.
Once you have the candidate set, apply the comparability filters:
- Drop properties with square footage outside ±25% of subject
- Drop properties with year built outside ±10 years of subject
- Drop properties with different construction class
- Drop properties with structural differences too large to adjust (e.g., 2-story when yours is single, or vice versa)
- Drop properties with material amenity differences without doing an adjustment
You should end up with 7-12 properties. If you have fewer than 5, widen one filter (typically square-footage range) one notch. If you have more than 15, the comp set is too loose — tighten filters.
Step 4: Capture the comparable set
Build a spreadsheet of your final comp set
For each comparable property, record:
- Address
- CAD account number (for cross-reference)
- Square footage
- Year built
- Current appraised value
- Per-square-foot appraised value = appraised value ÷ square footage
Most CAD portals let you copy data into a spreadsheet. Some let you export CSV directly. Manual transcription is fine for 10 properties — it takes 5 minutes.
Verify your data: a typo in square footage produces a misleading per-square-foot number. Double-check anything that looks like an outlier.
Step 5: Compute the median
Sort and compute the median per-square-foot appraised value
Sort your comp list by per-square-foot appraised value from low to high.
For an odd-count list (5, 7, 9, 11 properties), the median is the middle value.
For an even-count list (6, 8, 10, 12 properties), the median is the average of the two middle values.
Example with 9 properties sorted by per-sqft:
Median = $221 (the 5th value of 9)
Example with 8 properties:
Median = ($219 + $223) / 2 = $221 (average of 4th and 5th values)
The median is your defensible per-square-foot anchor for the protest.
Step 6: Apply the median to your property
Compute your target value
Target value = subject square footage × median per-square-foot appraised value
Example: your 2,400 square foot home × $221 median = $530,400 target value.
Compare to your current appraised value. If the current appraisal exceeds the target, you have a defensible §41.43(b)(3) protest. The difference between current and target is your potential reduction.
Step 7: Build the evidence packet PDF
Assemble the single-PDF evidence packet
Build a single PDF with these sections in order:
- Page 1: Summary
- Subject property address
- Current appraised value (CAD's number)
- Requested value (your target)
- Brief one-paragraph rationale citing §41.43(b)(3)
- Page 2-3: Comparable Properties Table
- Your comp table with all data captured in Step 4
- Median per-sqft computation
- Filter criteria you applied (so the CAD can verify)
- Page 4: Target Value Calculation
- Subject sqft × median per-sqft = target
- Difference vs. current appraised value
- Page 5+ (optional): Condition Adjustments
- Photos of any specific defects
- Contractor quotes or repair estimates
- Inspection reports if available
Upload via your CAD's portal evidence section. Bring printed copies to the hearing (3 for the panel, 1 for the CAD, 1 for yourself).
CAD-by-CAD search interface notes
Each Texas CAD's search interface has quirks. Notes on the major ones:
CCAD (Collin) — collincad.org
Excellent search. Account-holder portal exposes equity comps directly within iFile during protest season — login with your account and select "Comparables" on your property detail. Subdivision filter works well. Use this if you can.
DCAD (Dallas) — dallascad.org
Property search supports subdivision and neighborhood code filters. iSettle portal includes a "Comparable Properties" view for registered account-holders during protest season. Neighborhood codes are tight — use the code from your subject's detail page to find comps.
TAD (Tarrant) — tad.org
Search by subdivision name works. The uFile portal during protest season shows TAD's own comparable set for your property — useful both to see what TAD is using and as a starting point for your comp set (you'll typically refine TAD's set rather than copy it).
Denton CAD — dentoncad.com
Modern SaaS-backed search. Subdivision and neighborhood filters work cleanly. The portal exposes comps to registered users during protest season.
HCAD (Harris) — hcad.org
The most sophisticated search interface in Texas. Filter by neighborhood code, subdivision, square footage range, year built range — all from the search form. iFile portal exposes comparable properties tagged to your specific protest.
TCAD (Travis) — traviscad.org
Property search supports subdivision filter. Owner portal includes a comparable-properties view during protest season. Pull from the portal during protest filing rather than from the public search if you can.
BCAD (Bexar) — bcad.org
Subdivision filter works. The portal is less feature-rich than HCAD's but functional for the basic comp pull. Public search is straightforward.
Common pitfalls to avoid
1. Cherry-picking comps
The temptation is to pick only the lowest-appraised properties in your subdivision. The CAD will see this and attack the comp set as unreasonable. Always articulate your filter criteria. Pull every property that matches the criteria, not just the favorable ones.
2. Using too few comps
Three comps is the absolute minimum and is sometimes rejected as not "a reasonable number." Aim for 7-12. If your subdivision is small and only 5-6 comps exist within your filters, document that explicitly.
3. Mixing property types
A townhome comp does not work for a detached single-family subject. A 1-story doesn't work for a 2-story unless you adjust meaningfully. Stay within the same property class.
4. Ignoring CAD-published square footage errors
If your CAD record shows square footage that doesn't match reality (common on additions, renovations, or new construction), the per-sqft calculation will be wrong. Verify your square footage before computing.
5. Using market sale data instead of appraised values
Texas is a non-disclosure state — sale prices are not part of public records and the §41.43(b)(3) standard uses appraised values, not sale prices. Use the CAD's appraised value column, not Zillow / Realtor / MLS estimates.
6. Not noting the subdivision filter for the ARB
When you present at the formal ARB hearing, you'll be asked how you selected your comps. Have the filter criteria written down: "Same subdivision (Mountain Valley PH I), within 25% of my square footage (2,150-2,650 sqft), within 10 years of my year built (1979 ±10 = 1969-1989), single-family residential, no pool." The clearer your criteria, the harder for the CAD to attack the set.
FAQ
How do I find comparable properties for a Texas property tax protest?
Use your county appraisal district's free public property search. Pull properties in your immediate subdivision within ±25% of your square footage and ±10 years of your year built. Compute the median per-square-foot appraised value. Apply that median to your square footage. The result is your defensible target value under Texas Tax Code §41.43(b)(3).
How many comparable properties do I need?
5-10 is the sweet spot. Three is on the low end. More than 12 dilutes comp quality. Quality of the filter criteria matters more than count.
What counts as a "comparable" property in Texas?
Same subdivision or immediate neighborhood, ±25% square footage, ±10 years age, similar construction class, similar amenity profile. The §41.43(b)(3) standard requires "appropriately adjusted" — meaning either matched on these dimensions or with documented adjustments for differences.
Should I use Zillow or Redfin for Texas property tax comps?
No. Zillow's Zestimate is a market-value estimate, not an appraised value. The Texas unequal-appraisal argument uses appraised values from the CAD's own records. Use your CAD's public search exclusively for the §41.43(b)(3) calculation.
What if my subdivision is too small for 7+ comps?
Document that constraint explicitly. Pull every eligible property from your subdivision (even if only 4-6 exist). State in your packet: "Subject's subdivision (X) contains only [N] properties meeting the filter criteria; all are included in this comp set." A small but exhaustive set is more defensible than a larger set pulled from outside the subdivision.
Can the CAD use different comps than mine?
Yes. The CAD will typically present their own comp set — often with higher per-sqft values than yours. Request the CAD's evidence packet at least 14 days before any formal ARB hearing under §41.461. Review their comps for filter violations, mismatched features, and adjustment issues. Address each in your rebuttal.
How long should this take?
About 45 minutes total: 2 min to open the CAD portal, 3 min for subject data, 10 min for filter and capture, 10 min to compile the comp spreadsheet, 5 min for median computation and target calculation, 15 min for the packet PDF. First-time protesters often spend longer (1-2 hours); experienced ones do it in 30 minutes.
TaxStand pulls and filters the comps for you.
Our packet includes the full comp pull, median calculation, target value, and a ready-to-submit PDF. $199 flat. You file the protest, you keep 100% of the savings.
Get on the list for 2027 protest seasonThis article is for general educational use and does not constitute legal or tax advice. The §41.43(b)(3) unequal-appraisal standard is from the Texas Tax Code; verify current text on the Texas Legislature's online statute portal. CAD search interfaces are subject to change.
TaxStand is a service of Outlaw Holdings LLC. We do not represent homeowners at hearings.