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Single Family ResidenceResidential
$24,900$28 / 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 76How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Aug 30, 2026

818 UNION ST

ALTON, IL 62002
1
Baths
897 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.
0.25 ac
Lot SizeThe size of the land the home sits on, from county records.
1905
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.

Valuation

$25K
$19K low$31K high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$480 (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.$5,990 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$3,190
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$2,800
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$23,870
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$17,970

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.31
1
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
1
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
82
HeatProjected heat risk, scored 0 to 100, based on how many extremely hot days a year are expected. Higher is riskier.
70
StormProjected risk from heavy rainstorms, scored 0 to 100, based on how often extreme rainfall is expected. Higher is riskier.
4
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 Residence
CountyMADISON
Lot (acres)The size of the land the home sits on, from county records.0.25
ConstructionThe main material the home's frame and walls are built from.Frame (Unspecified)
RoofThe main material covering the roof, such as asphalt shingle or tile.Shingle
HeatingThe type of heating system in the home.Yes
GarageWhether the property has a garage, and details like whether it is attached to the home.Garage, Detached
PoolWhether the property has a pool, and what kind, such as in-ground.No

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.

M
Alton Middle SchoolC-
Middle · Grades 6–8 · 1.1 mi
H
Alton High SchoolD+
High · Grades 9–12 · 2.8 mi
E
Lewis & Clark Elementary School
Elementary · Grades KG–1 · 4.9 mi

District: Alton Community Unit School District 11

Neighborhood · ZIP 62002These 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.135
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.85
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.125

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.89%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.16%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.19%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.1%
PopulationHow many people live in this area.28,813
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.738 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$61,207
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$78,082
Average tempThe average temperature here across a full year.55°F
Annual precipHow much rain and melted snow falls here in a typical year.39 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.59%

Owner Tools

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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

818 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.

  • Among the least valuable homes in Madison County
  • Among the lowest price per square foot in Madison County
  • Smaller than 76% of homes in Madison County
  • Has a bigger lot than 67% of homes in Alton 62002
  • Older than 97% of homes in Madison County

What homes are worth in Alton 62002

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

This home
$23K$442K

This home is worth more than 2% of homes in Alton 62002.

How it measures up in Alton 62002

The dot is this home. The mark in the middle is the typical home in Alton 62002.

Estimated value$24,900
CheaperTypical $107,151Pricier

Pricier than 2% of homes nearby

Price per ft²$28
CheaperTypical $107Pricier

Pricier than 2% of homes nearby

Living area897 ft²
SmallerTypical 1,008 ft²Bigger

Bigger than 34% of homes nearby

Lot size0.25 ac
SmallerTypical 0.19 acBigger

Bigger than 67% of homes nearby

Year built1905
OlderTypical 1948Newer

Newer than 8% of homes nearby

How 818 Union St ranks against every home in each area.
MeasureThis homeAlton 62002Madison County
Estimated valuepricier than$24,9002% of homesalmost no homes
Price per ft²pricier than$282% of homesalmost no homes
Living areabigger than897 ft²34% of homes24% of homes
Lot sizebigger than0.25 ac67% of homes50% of homes
Year builtnewer than19058% of homes3% of homes

About 818 Union St

How much is 818 Union St, Alton, IL worth?

The TopHap Estimate for 818 Union St, Alton, IL is $24,900 as of Aug 30, 2026. The likely range is $18,925 to $30,875. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 818 Union St, Alton, IL last sell?

818 Union St, Alton, IL last sold on Sep 11, 2023, according to the county's recorded deed.

How big is 818 Union St, Alton, IL?

818 Union St, Alton, IL has 1 bathrooms, 897 square feet of living space and a 0.25-acre lot.

When was 818 Union St, Alton, IL built?

818 Union St, Alton, IL was built in 1905, making it 121 years old. The building has 1 story.

What schools serve 818 Union St, Alton, IL?

818 Union St, Alton, IL is assigned to Alton Middle School (middle), rated C-; Alton High School (high), rated D+; Lewis & Clark Elementary School (elementary). All sit in Alton Community Unit School District 11. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 818 Union St, Alton, IL compare to other homes in Alton 62002?

Among the 12,598 homes in Alton 62002, it is worth more than 2% of them ($24,900 against a typical $107,151), its price per square foot is higher than 2% of them ($28 against a typical $107), it is bigger than 34% of them (897 ft² against a typical 1,008 ft²), its lot is bigger than 67% of them (0.25 ac against a typical 0.19 ac) and it is newer than 8% of them (1905 against a typical 1948). Measured against all of Madison County, it is worth more than almost no 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 818 Union St, Alton, IL?

The 2025 property tax bill for 818 Union St, Alton, IL was $480. The county assessed it at $5,990.

More homes on Union St

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Assigned schools

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