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

3900 BONNIE LN, ROUND ROCK, TX 78665

ROUND ROCK, 78665 — williamson County

4 bed2 bath1,810 sqftBuilt 1999

Property at a Glance

This home is estimated between $333,527 and $445,660, with a best estimate of $437,264. 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

$333,527 $445,660
Best Estimate
$437,264
WCAD Value
$466,894
Medium Confidence

Based on 5 comparable properties(4 in the same subdivision)

Based on 5 comparable properties (4 in the same subdivision, 1 nearby), the estimated range is $333,527 and $445,660. More comparables in the same subdivision would strengthen this estimate.

Comparable Properties (5)

3902 BONNIE LN, ROUND ROCK, TX 78665
0.01 mi 100% similar Same subdivision
4 bed 3 bath 1,683 sqft Built 2004
Raw Value $395,698
Adjusted Value $445,660

Adjusted +$29,406 for 127 sqft more living space and +$20,556 for being newer. Net adjustment: +$49,962.

1527 LORSON LOOP, ROUND ROCK, TX 78665
0.02 mi 100% similar Same subdivision
4 bed 3 bath 1,688 sqft Built 2004
Raw Value $393,568
Adjusted Value $442,373

Adjusted +$28,249 for 122 sqft more living space and +$20,556 for being newer. Net adjustment: +$48,805.

3904 BONNIE LN, ROUND ROCK, TX 78665
0.02 mi 100% similar Same subdivision
3 bed 2 bath 1,822 sqft Built 2004
Raw Value $320,950
Adjusted Value $338,727

Adjusted -$2,779 for 12 sqft less living space and +$20,556 for being newer. Net adjustment: +$17,777.

4 bed 2 bath 1,877 sqft Built 1996
Raw Value $465,112
Adjusted Value $437,264

Adjusted -$15,514 for 67 sqft less living space and -$12,334 for being older. Net adjustment: -$27,848.

1529 LORSON LOOP, ROUND ROCK, TX 78665
0.03 mi 100% similar Same subdivision
3 bed 2 bath 1,822 sqft Built 2003
Raw Value $319,861
Adjusted Value $333,527

Adjusted -$2,779 for 12 sqft less living space and +$16,445 for being newer. Net adjustment: +$13,666.

The Neighborhood

This home is valued 42.3% 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

above average
197 Properties
$328,056 Median Value
-4.7% YoY Change
0% Have Pool
100% Have Garage
This Home
$466,894
Median
$328,056

This home is +42.3% above the subdivision median.

Tax Analysis

The estimated annual property tax is $8,401 across all districts. With a homestead exemption claimed, that drops to $7,064 — saving $1,337 per year. That's $589 per month a buyer should budget. The assessed value increased +5.2% vs the subdivision average of -4.7%. This above-average increase gives a protest opportunity score of 55 out of 100 — it may be worth challenging the appraisal.

Tax Districts

DistrictTypeRateAnnual Amount
Round Rock ISDSchool0.8931%$4,170
Round RockCity0.3720%$1,737
Williamson CountyCounty0.3694%$1,725
Austin Community Collegespecial0.1034%$483
Williamson County FM/RdCounty0.0443%$207
Upper Brushy Creek WCIDWater0.0170%$79
Williamson Central Appraisal Districtcad0.0000%$0
Total Annual Tax1.7993%$8,401
55 / 100

Moderate opportunity to protest.

Mortgage Context

At today's 30-year mortgage rate of 6.38%, a buyer financing $437,264 would pay approximately $2,729 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