Cook County Value

12375 Thornberry Dr Lemont, IL 60439

4 bed / 2 bath, 3,944 sqft, built 2006, in Lemont. Assessor market value for 2026: $900,000.

Cook County account 22303120050000

In line with similar homes

8 similar homes nearby support a value at or above your county value.

Assessor market value$900,000
Similar homes$927,510
No gap: similar homes are at or above the county value · bars start at $0

How sure: High · 8 similar homes (5 shown below) · public records only

Assessor market value
$900,000
Tax year 2026 · before exemptions; the assessed value on your notice is 10% of it
Living area
3,944 sqft
$228 per sqft
Year built
2006
Average quality

What we found

Similar homes' assessments

Weak

2 of 8 similar homes are assessed lower per square foot. Their similarity-weighted median is $235.17/sqft, which supports a value of $927,510.

Compare this assessment

Start with the county value and property facts, then review appraisal comps, recent sales, and prior-year changes to decide whether the assessment is worth challenging. The comps on this page are free to review; email sign-in is only used to save a printable report.

For nearby context, browse ZIP 60439 and Lemont assessment pages.

Local guide: Lemont Township 2026 Property Tax Appeal Guide.

Appeal deadlines

For Lemont, appeals to the Assessor closed . Board of Review dates for Lemont have not been published yet.

Deadline rule: Set by township: file with the Assessor by your township's last file date, and with the Board of Review while your township is open there. Evidence is reviewed by the Cook County Assessor's Office or, in a separate appeal, by the Cook County Board of Review. Dates checked against the official source.

Assessment snapshot

These public CCAO records highlight what may be worth checking before you file.

  • Assessment changeThe assessor market value increased 28.9% from $698,470 in 2025 to $900,000 in 2026.
  • Assessor market value per square footThe current public record shows about $228 per square foot before any comparable-property adjustments.
  • Nearby comparison areaThis page starts the equity review with public records for the Lemont neighborhood and ZIP 60439.
  • Neighborhood value signalAmong 380 residential records in the same neighborhood, the average assessor market value is about $246 per square foot.
  • Area year-over-year signalNearby residential records with prior-year values moved about +25.8% on average.

Comparable assessments

Showing 5 of the 8 similar homes in this property's equity comparison, from public appraisal records.

  • 12504 Thornberry Dr Lemont, IL 60439
    3,910 sqft | $243/sqft | built 2005 | Similar size (3,910 vs 3,944 sqft); Similar age (2005 vs 2006); Similar lot size (12,466 vs 12,439 sqft)
    $950,000
  • 12282 St. James Way Lemont, IL 60439
    3,825 sqft | $233/sqft | built 2004 | Similar size (3,825 vs 3,944 sqft); Similar age (2004 vs 2006); Similar lot size (12,596 vs 12,439 sqft)
    $890,010
  • 12507 Briarcliffe Dr Lemont, IL 60439
    3,961 sqft | $227/sqft | built 2005 | Similar size (3,961 vs 3,944 sqft); Similar age (2005 vs 2006); Similar lot size (12,419 vs 12,439 sqft)
    $900,000
  • 12395 Thornberry Dr Lemont, IL 60439
    3,742 sqft | $235/sqft | built 2005 | 5% smaller (3,742 vs 3,944 sqft); Similar age (2005 vs 2006); Similar lot size (12,356 vs 12,439 sqft)
    $880,010
  • 13583 Cambridge Dr Lemont, IL 60439
    3,914 sqft | $243/sqft | built 2006 | Similar size (3,914 vs 3,944 sqft); Built same year (2006); Similar lot size (13,512 vs 12,439 sqft)
    $950,000

Recent comparable sales

Sales selected by similarity to the subject property.

Public appraisal comparison for 2026. Prepared . Appraisal source: Cook County Assessor's Office. Sales data checked in this snapshot: . Matches consider available size, age, location and property characteristics. How comparisons work.

Value history

Up 28.9% in 2026 from 2025.

Assessor market value by tax year, with the change from the previous year listed
Tax yearAssessor market valueChangeChange %
2026$900,000+$201,530+28.9%
2025$698,470−$31,530−4.3%
2024$730,000$00.0%
2023$730,000+$120,010+19.7%
2022$609,990$00.0%
2021$609,990−$54,390−8.2%
2020$664,380——
6-year total+$235,620+35.5%