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Single Family ResidenceResidential
$503,398$219 / ft²
TopHap EstimateOur estimate of what this home would sell for today, based on nearby sales, the home's size and features, and local price trends. It is a starting point, not an appraisal.· confidence 95How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Jun 23, 2026

3921 SAPPHIRE LOOP

ROUND ROCK, TX 78681
2
Baths
2,300 ft²
Living AreaTotal finished area of the structures, from county records. Some counties include shared space like hallways or a building gym, so it may not match a listing.
2007
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
2
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.
2
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$503K
$478K low$529K high
Est. Owner EquityRoughly how much of the home's value the owner would keep after paying off known loans. It is our estimate minus the loans still owed.$284,773
Est. Lendable EquityThe part of the owner's equity a lender would typically let them borrow against — about 80% of their equity.$227,818
Loan-to-ValueHow much is still owed on the home compared to what it is worth. 80% means loans equal 80% of our estimate, so it shifts when the estimate does.43%
1st MortgageA loan still believed to be open on this home, in the order lenders get repaid. The first position is paid back before the second.$218,625
AUSTIN FIRST MORTGAGE · recorded Dec 1, 2016

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$10,521 (2025)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$550,074 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$128,000
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$422,074
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$550,074
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$550,074

Climate Risk

Overall riskThe average of the five hazard scores below, on a 0 to 100 scale. Higher means greater projected risk over the coming decades.56
35
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
54
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
100
HeatProjected heat risk, scored 0 to 100, based on how many extremely hot days a year are expected. Higher is riskier.
48
StormProjected risk from heavy rainstorms, scored 0 to 100, based on how often extreme rainfall is expected. Higher is riskier.
46
DroughtProjected water shortage risk, scored 0 to 100. Higher means more strain on the local water supply.
Projected Flood DepthHow deep a serious flood is expected to get here at some point in the next 30 years. Shown in inches.7 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.6%
FEMA Flood ZoneFEMA's flood zone for this address. Zones starting with A or V are high risk, and lenders usually require flood insurance there.1 percent flood zone

Scores 0–100; higher = greater projected risk.

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountyWilliamson
Effective Year BuiltAn adjusted build year that accounts for condition and major remodels. A big renovation can make a home count as newer than it is.2008
FoundationWhat the home is built on, such as a concrete slab, a crawl space, or a basement.Mat/Raft Foundation (Slab)
HeatingThe type of heating system in the home.Central
CoolingThe type of cooling or air conditioning in the home.Central
FireplaceWhether the home has a fireplace, and what kind.Yes
PoolWhether the property has a pool, and what kind, such as in-ground.No
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.Porch · 172 ft²

Transaction History(3)

Sales and refinances filed with the county for this home. Not every transfer is a normal sale, so check the type before comparing prices.

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

E
Akin Elementary SchoolA-
Elementary · Grades KG–5 · 2.3 mi
M
Stiles Middle SchoolA+
Middle · Grades 6–8 · 2.3 mi
H
Rouse High SchoolA-
High · Grades 9–12 · 4.1 mi

District: Leander Independent School District

Neighborhood · ZIP 78681These are comparison scores, not percentages. 100 equals the national average, so 150 means about 50% above average.

CrimeLocal crime compared with the rest of the country, where 100 is average. It reflects things like population density, income, and how crime gets reported.44
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.86
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.20

Index scale: 100 = US average (tick). Lower is better.

Homes occupiedThe share of homes here that someone lives in. The rest sit empty, including vacation and for-sale homes.98%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.38%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.4.9%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.4%
PopulationHow many people live in this area.72,545
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.3,224 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$126,547
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$146,868
Average tempThe average temperature here across a full year.67°F
Annual precipHow much rain and melted snow falls here in a typical year.35 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.60%

Ownership

OccupancyWhether the owner appears to live here or somewhere else. It is inferred from the mailing address on record.Absentee owner
Company ownedWhether the owner is a company or trust rather than a person.No

Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

How this home compares

3921 Sapphire Loop measured against every home in its neighborhood, its ZIP code and its county, using county assessor records refreshed nightly. A home can stand out in one of those areas and look ordinary in another, because each one holds a different mix of homes.

  • Worth more than 69% of homes in Williamson County
  • Costs more per square foot than 73% of homes in Mayfield Ranch
  • Smaller than 67% of homes in Mayfield Ranch
  • Newer than 81% of homes in Round Rock 78681

What homes are worth in Round Rock 78681

Each bar is how many homes fall in that price range. The marker is this home.

This home
$256K$1.1M

This home is worth more than 52% of homes in Round Rock 78681.

How it measures up in Round Rock 78681

The dot is this home. The mark in the middle is the typical home in Round Rock 78681.

Estimated value$503,398
CheaperTypical $498,013Pricier

Pricier than 52% of homes nearby

Price per ft²$219
CheaperTypical $219Pricier

Pricier than 50% of homes nearby

Living area2,300 ft²
SmallerTypical 2,315 ft²Bigger

Bigger than 49% of homes nearby

Year built2007
OlderTypical 1998Newer

Newer than 81% of homes nearby

How 3921 Sapphire Loop ranks against every home in each area.
MeasureThis homeMayfield RanchRound Rock 78681Williamson County
Estimated valuepricier than$503,39842% of homes52% of homes69% of homes
Price per ft²pricier than$21973% of homes50% of homes66% of homes
Living areabigger than2,300 ft²33% of homes49% of homes59% of homes
Year builtnewer than200733% of homes81% of homes52% of homes

About 3921 Sapphire Loop

How much is 3921 Sapphire Loop, Round Rock, TX worth?

The TopHap Estimate for 3921 Sapphire Loop, Round Rock, TX is $503,398 as of Jun 23, 2026. The likely range is $478,228 to $528,567. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 3921 Sapphire Loop, Round Rock, TX last sell?

3921 Sapphire Loop, Round Rock, TX last sold on Dec 1, 2016, according to the county's recorded deed.

How big is 3921 Sapphire Loop, Round Rock, TX?

3921 Sapphire Loop, Round Rock, TX has 2 bathrooms and 2,300 square feet of living space.

When was 3921 Sapphire Loop, Round Rock, TX built?

3921 Sapphire Loop, Round Rock, TX was built in 2007, making it 19 years old. The building has 1 story.

What schools serve 3921 Sapphire Loop, Round Rock, TX?

3921 Sapphire Loop, Round Rock, TX is assigned to Akin Elementary School (elementary), rated A-; Stiles Middle School (middle), rated A+; Rouse High School (high), rated A-. All sit in Leander Independent School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 3921 Sapphire Loop, Round Rock, TX compare to other homes in Round Rock 78681?

Among the 18,081 homes in Round Rock 78681, it is worth more than 52% of them ($503,398 against a typical $498,013), its price per square foot is higher than 50% of them ($219 against a typical $219), it is bigger than 49% of them (2,300 ft² against a typical 2,315 ft²) and it is newer than 81% of them (2007 against a typical 1998). Measured against all of Williamson County, it is worth more than 69% of homes there. These shares are recounted nightly from the full county assessor record for each area, not from active listings.

What are the property taxes on 3921 Sapphire Loop, Round Rock, TX?

The 2025 property tax bill for 3921 Sapphire Loop, Round Rock, TX was $10,521. The county assessed it at $550,074.

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