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Single Family ResidentialResidential
$311,431
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 93How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Sep 24, 2026
Last sold for $226,000 on Apr 3, 2019

640 UNION ST

PLATTEVILLE, WI 53818
0
Baths
0.43 ac
Lot SizeThe size of the land the home sits on, from county records.

Valuation

$311K
$289K low$334K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$226,000 · Apr 3, 2019

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$4,318 (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.$275,100 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$33,700
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$241,400
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$288,100

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.32
1
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
31
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
67
HeatProjected heat risk, scored 0 to 100, based on how many extremely hot days a year are expected. Higher is riskier.
58
StormProjected risk from heavy rainstorms, scored 0 to 100, based on how often extreme rainfall is expected. Higher is riskier.
5
DroughtProjected water shortage risk, scored 0 to 100. Higher means more strain on the local water supply.

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 Residential
CountyGRANT
Lot (acres)The size of the land the home sits on, from county records.0.43
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(1)

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.

M
Platteville Middle SchoolA-
Middle · Grades 4–8 · 0.6 mi
E
Neal Wilkins Early Learning Center
Elementary · Grades EE–1 · 0.9 mi
H
Platteville High SchoolA
High · Grades 9–12 · 1.1 mi

District: Platteville School District

Neighborhood · ZIP 53818These 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.103
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.81
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.19

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.91%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.22%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.17%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.0%
PopulationHow many people live in this area.15,533
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.101 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$60,639
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$79,860
Average tempThe average temperature here across a full year.47°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.54%

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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

640 Union St 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 79% of homes in Grant County

What homes are worth in Platteville 53818

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

This home
$86K$588K

This home is worth more than 71% of homes in Platteville 53818.

How it measures up in Platteville 53818

The dot is this home. The mark in the middle is the typical home in Platteville 53818.

Estimated value$311,431
CheaperTypical $237,539Pricier

Pricier than 71% of homes nearby

Lot size0.43 ac
SmallerTypical 0.38 acBigger

Bigger than 54% of homes nearby

How 640 Union St ranks against every home in each area.
MeasureThis homePlatteville 53818Grant County
Estimated valuepricier than$311,43171% of homes79% of homes
Lot sizebigger than0.43 ac54% of homes55% of homes

About 640 Union St

How much is 640 Union St, Platteville, WI worth?

The TopHap Estimate for 640 Union St, Platteville, WI is $311,431 as of Sep 24, 2026. The likely range is $288,762 to $334,100. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 640 Union St, Platteville, WI last sell?

640 Union St, Platteville, WI last sold on Apr 3, 2019 for $226,000, according to the county's recorded deed.

What schools serve 640 Union St, Platteville, WI?

640 Union St, Platteville, WI is assigned to Platteville Middle School (middle), rated A-; Neal Wilkins Early Learning Center (elementary); Platteville High School (high), rated A. All sit in Platteville School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 640 Union St, Platteville, WI compare to other homes in Platteville 53818?

Among the 3,479 homes in Platteville 53818, it is worth more than 71% of them ($311,431 against a typical $237,539) and its lot is bigger than 54% of them (0.43 ac against a typical 0.38 ac). Measured against all of Grant County, it is worth more than 79% 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 640 Union St, Platteville, WI?

The 2025 property tax bill for 640 Union St, Platteville, WI was $4,318. The county assessed it at $275,100.

More homes on Union St

Closest homes

More homes in Platteville 53818

Assigned schools

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