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12100 GREY ROCK LN, AUSTIN, TX 78750

AUSTIN, 78750 — williamson County

4 bed2 bath1,653 sqftBuilt 1977

Property at a Glance

This home is estimated between $383,471 and $458,191, with a best estimate of $401,014. That places the property above the R3P5480G - Anderson Mill 12,16 - 20 - Partially in TCAD median of $387,608, in a neighborhood that declined 7.3% over the past year.

Estimated Value Range

$383,471 $458,191
Best Estimate
$401,014
WCAD Value
$445,298
High Confidence

Based on 5 comparable properties(5 in the same subdivision)

Based on 5 comparable properties in R3P5480G - Anderson Mill 12,16 - 20 - Partially in TCAD, this home's estimated market value is between $383,471 and $458,191. All 5 comparables are in the same subdivision, giving this estimate high confidence.

Comparable Properties (5)

12102 GREY ROCK LN, AUSTIN, TX 78750
0.01 mi 100% similar Same subdivision
3 bed 2 bath 1,403 sqft Built 1977
Raw Value $396,610
Adjusted Value $458,191

Adjusted +$61,581 for 250 sqft more living space. Net adjustment: +$61,581.

12006 GREY ROCK LN, AUSTIN, TX 78750
0.01 mi 100% similar Same subdivision
3 bed 2 bath 1,498 sqft Built 1979
Raw Value $355,273
Adjusted Value $383,471

Adjusted +$38,180 for 155 sqft more living space and -$9,982 for being older. Net adjustment: +$28,198.

12104 GREY ROCK LN, AUSTIN, TX 78750
0.02 mi 100% similar Same subdivision
3 bed 2 bath 1,505 sqft Built 1977
Raw Value $355,419
Adjusted Value $391,875

Adjusted +$36,456 for 148 sqft more living space. Net adjustment: +$36,456.

12103 ACORN CREEK TRL, AUSTIN, TX 78750
0.02 mi 100% similar Same subdivision
3 bed 2 bath 1,645 sqft Built 1977
Raw Value $399,043
Adjusted Value $401,014

Adjusted +$1,971 for 8 sqft more living space. Net adjustment: +$1,971.

12004 GREY ROCK LN, AUSTIN, TX 78750
0.02 mi 100% similar Same subdivision
3 bed 2 bath 1,410 sqft Built 1977
Raw Value $344,616
Adjusted Value $404,472

Adjusted +$59,856 for 243 sqft more living space. Net adjustment: +$59,856.

The Neighborhood

This home is valued 14.9% above the R3P5480G - Anderson Mill 12,16 - 20 - Partially in TCAD median of $387,608. With 834 homes in the subdivision, the property sits in the upper tier. Note that values in this subdivision declined 7.3% over the past year.

R3P5480G - Anderson Mill 12,16 - 20 - Partially in TCAD

typical
834 Properties
$387,608 Median Value
-7.3% YoY Change
2% Have Pool
97% Have Garage
This Home
$445,298
Median
$387,608

This home is +14.9% above the subdivision median.

Tax Analysis

The estimated annual property tax is $9,243 across all districts. With a homestead exemption claimed, that drops to $7,443 — saving $1,800 per year. That's $620 per month a buyer should budget. The assessed value increased roughly in line with the neighborhood, so a tax protest is unlikely to yield significant savings.

Tax Districts

DistrictTypeRateAnnual Amount
Round Rock ISDSchool0.8931%$3,977
AustinCity0.5240%$2,333
Williamson CountyCounty0.3694%$1,645
Anderson Mill Limited Districtspecial0.1243%$554
Austin Community Collegespecial0.1034%$460
Williamson County FM/RdCounty0.0443%$197
Upper Brushy Creek WCIDWater0.0170%$76
Williamson Central Appraisal Districtcad0.0000%$0
Total Annual Tax2.0756%$9,243

Mortgage Context

At today's 30-year mortgage rate of 6.38%, a buyer financing $401,014 would pay approximately $2,503 per month (principal and interest only, excluding taxes and insurance).

Data sourced from Williamson County Appraisal District (WCAD), Texas Education Agency (TEA), and Federal Reserve Economic Data (FRED). Assessment values reflect the appraisal district's estimate, not market sale prices. Report generated 4/18/2026.

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