Cook County Value

12404 Thornberry Dr Lemont, IL 60439

5 bed / 4 bath, 3,681 sqft, built 2018, in Lemont. Assessor market value for 2026: $940,000.

Cook County account 22303090080000

Assessor market value
$940,000
Tax year 2026 · before exemptions; the assessed value on your notice is 10% of it
Living area
3,681 sqft
$255 per sqft
Year built
2018
Average quality

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 35.2% from $695,010 in 2025 to $940,000 in 2026.
  • Assessor market value per square footThe current public record shows about $255 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.

  • 12364 Thornberry Dr Lemont, IL 60439
    3,748 sqft | $248/sqft | built 2016 | Similar size (3,748 vs 3,681 sqft); Similar age (2016 vs 2018); Similar lot size (12,213 vs 12,728 sqft)
    $930,000
  • 12374 Thornberry Dr Lemont, IL 60439
    3,634 sqft | $245/sqft | built 2014 | Similar size (3,634 vs 3,681 sqft); Similar age (2014 vs 2018); Similar lot size (12,411 vs 12,728 sqft)
    $890,000
  • 12614 Thornberry Dr Lemont, IL 60439
    3,731 sqft | $260/sqft | built 2013 | Similar size (3,731 vs 3,681 sqft); Similar age (2013 vs 2018); Similar lot size (12,904 vs 12,728 sqft)
    $970,000
  • 12574 Thornberry Dr Lemont, IL 60439
    3,702 sqft | $262/sqft | built 2016 | Similar size (3,702 vs 3,681 sqft); Similar age (2016 vs 2018); Lot 13% larger (14,444 vs 12,728 sqft)
    $970,010
  • 13527 Cambridge Dr Lemont, IL 60439
    3,489 sqft | $289/sqft | built 2017 | 5% smaller (3,489 vs 3,681 sqft); Similar age (2017 vs 2018); Similar lot size (13,777 vs 12,728 sqft)
    $1,010,000

Recent comparable sales

Sales selected by similarity to the subject property.

  • 12554 Eileen St Lemont, IL 60439
    June-29-2026 | 3,421 sqft | $272/sqft | built 2025 | 7% size difference (3,421 sqft); Moderate age difference (7 years newer); Sold after the valuation date
    $930,895
  • 12655 Derry Dr Lemont, IL 60439
    June-29-2026 | 2,672 sqft | $266/sqft | built 2025 | Moderate age difference (7 years newer); Sold after the valuation date
    $710,150

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 35.2% in 2026 from 2025.

Assessor market value by tax year, with the change from the previous year listed
Tax yearAssessor market valueChangeChange %
2026$940,000+$244,990+35.2%
2025$695,010$00.0%
2024$695,010−$104,990−13.1%
2023$800,000+$279,310+53.6%
2022$520,690−$22,070−4.1%
2021$542,760−$41,220−7.1%
2020$583,980——
6-year total+$356,020+61.0%