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509/511 SIERRA CV, ROUND ROCK, TX 78664

ROUND ROCK, 78664 — williamson County

3 bed4 bath1,815 sqftBuilt 1984

Property at a Glance

This home is estimated between $315,358 and $439,838, with a best estimate of $368,500. That places the property above the R450X - Round Rock East - Duplex median of $355,449, in a neighborhood that declined 8.7% over the past year.

Estimated Value Range

$315,358 $439,838
Best Estimate
$368,500
WCAD Value
$339,475
High Confidence

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

Based on 5 comparable properties in R450X - Round Rock East - Duplex, this home's estimated market value is between $315,358 and $439,838. All 5 comparables are in the same subdivision, giving this estimate high confidence.

Comparable Properties (5)

506/508 SIERRA CV, ROUND ROCK, TX 78664
0.00 mi 100% similar Same subdivision
3 bed 4 bath 2,048 sqft Built 1984
Raw Value $360,633
Adjusted Value $315,358

Adjusted -$45,275 for 233 sqft less living space. Net adjustment: -$45,275.

501/503 SIERRA CV, ROUND ROCK, TX 78664
0.00 mi 100% similar Same subdivision
3 bed 4 bath 1,586 sqft Built 1984
Raw Value $324,502
Adjusted Value $369,000

Adjusted +$44,498 for 229 sqft more living space. Net adjustment: +$44,498.

1600 VILLA CV, ROUND ROCK, TX 78664
0.00 mi 100% similar Same subdivision
5 bed 4 bath 1,652 sqft Built 1979
Raw Value $403,164
Adjusted Value $439,838

Adjusted +$31,673 for 163 sqft more living space and +$5,001 for being newer. Net adjustment: +$36,674.

502/504 SIERRA CV, ROUND ROCK, TX 78664
0.00 mi 100% similar Same subdivision
3 bed 4 bath 1,586 sqft Built 1984
Raw Value $324,002
Adjusted Value $368,500

Adjusted +$44,498 for 229 sqft more living space. Net adjustment: +$44,498.

505/507 SIERRA CV, ROUND ROCK, TX 78664
0.00 mi 100% similar Same subdivision
3 bed 4 bath 2,048 sqft Built 1984
Raw Value $360,843
Adjusted Value $315,568

Adjusted -$45,275 for 233 sqft less living space. Net adjustment: -$45,275.

The Neighborhood

This home is valued 4.5% below the R450X - Round Rock East - Duplex median of $355,449. That positions it competitively for buyers comparing within the neighborhood. Note that values in this subdivision declined 8.7% over the past year.

R450X - Round Rock East - Duplex

typical
836 Properties
$355,449 Median Value
-8.7% YoY Change
0% Have Pool
84% Have Garage
This Home
$339,475
Median
$355,449

This home is -4.5% below the subdivision median.

Tax Analysis

The estimated annual property tax is $6,108 across all districts. With a homestead exemption claimed, that drops to $4,795 — saving $1,313 per year. That's $400 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%$3,032
Round RockCity0.3720%$1,263
Williamson CountyCounty0.3694%$1,254
Austin Community Collegespecial0.1034%$351
Williamson County FM/RdCounty0.0443%$150
Upper Brushy Creek WCIDWater0.0170%$58
Williamson Central Appraisal Districtcad0.0000%$0
Total Annual Tax1.7993%$6,108

Mortgage Context

At today's 30-year mortgage rate of 6.38%, a buyer financing $368,500 would pay approximately $2,300 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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