Beta Williamson County, TX only — data and coverage are limited during early access.

3600 SANDY BROOK DR, ROUND ROCK, TX 78665

ROUND ROCK, 78665 — williamson County

3 bed2 bath1,864 sqftBuilt 2007

Property at a Glance

This home is estimated between $280,519 and $531,076, with a best estimate of $342,919. That places the property above the R409599G - STONEY BROOK - ALL SECTIONS median of $328,056, in a neighborhood that declined 4.7% over the past year.

Estimated Value Range

$280,519 $531,076
Best Estimate
$342,919
WCAD Value
$334,916
High Confidence

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

Based on 5 comparable properties in R409599G - STONEY BROOK - ALL SECTIONS, this home's estimated market value is between $280,519 and $531,076. All 5 comparables are in the same subdivision, giving this estimate high confidence.

Comparable Properties (5)

1515 HAYNIE BND, ROUND ROCK, TX 78665
0.02 mi 100% similar Same subdivision
3 bed 2 bath 1,982 sqft Built 2007
Raw Value $307,841
Adjusted Value $280,519

Adjusted -$27,322 for 118 sqft less living space. Net adjustment: -$27,322.

1519 HAYNIE BND, ROUND ROCK, TX 78665
0.02 mi 100% similar Same subdivision
3 bed 2 bath 1,878 sqft Built 2007
Raw Value $320,453
Adjusted Value $317,211

Adjusted -$3,242 for 14 sqft less living space. Net adjustment: -$3,242.

3608 SANDY BROOK DR, ROUND ROCK, TX 78665
0.02 mi 100% similar Same subdivision
3 bed 2 bath 1,571 sqft Built 2006
Raw Value $281,866
Adjusted Value $345,598

Adjusted +$67,843 for 293 sqft more living space and -$4,111 for being older. Net adjustment: +$63,732.

1500 HAYNIE BND, ROUND ROCK, TX 78665
0.03 mi 100% similar Same subdivision
3 bed 2 bath 1,751 sqft Built 2007
Raw Value $316,754
Adjusted Value $342,919

Adjusted +$26,165 for 113 sqft more living space. Net adjustment: +$26,165.

1523 HAYNIE BND, ROUND ROCK, TX 78665
0.03 mi 100% similar Same subdivision
3 bed 2 bath 1,260 sqft Built 2009
Raw Value $382,999
Adjusted Value $531,076

Adjusted +$139,854 for 604 sqft more living space and +$8,223 for being newer. Net adjustment: +$148,077.

The Neighborhood

This home is valued 2.1% above the R409599G - STONEY BROOK - ALL SECTIONS median of $328,056. With 197 homes in the subdivision, the property sits in the upper tier. Note that values in this subdivision declined 4.7% over the past year.

R409599G - STONEY BROOK - ALL SECTIONS

typical
197 Properties
$328,056 Median Value
-4.7% YoY Change
0% Have Pool
100% Have Garage
This Home
$334,916
Median
$328,056

This home is +2.1% above the subdivision median.

Tax Analysis

The estimated annual property tax is $6,026 across all districts. With a homestead exemption claimed, that drops to $4,714 — saving $1,312 per year. That's $393 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%$2,991
Round RockCity0.3720%$1,246
Williamson CountyCounty0.3694%$1,237
Austin Community Collegespecial0.1034%$346
Williamson County FM/RdCounty0.0443%$148
Upper Brushy Creek WCIDWater0.0170%$57
Williamson Central Appraisal Districtcad0.0000%$0
Total Annual Tax1.7993%$6,026

Mortgage Context

At today's 30-year mortgage rate of 6.38%, a buyer financing $342,919 would pay approximately $2,140 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.

View full property details