512 Porter St Lemont, IL 60439

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 September 29, 2026. 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 September 27, 2026 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 17.9% from $280,000 in 2025 to $330,000 in 2026.
• Assessor market value per square footThe current public record shows about $176 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 1,277 residential records in the same neighborhood, the average assessor market value is about $255 per square foot.
• Area year-over-year signalNearby residential records with prior-year values moved about +25.5% on average.

Public appraisal comparison for 2026. Prepared October 15, 2026. Appraisal source: Cook County Assessor's Office. Sales data checked in this snapshot: October 13, 2026. Matches consider available size, age, location and property characteristics. How comparisons work.

Value history

Up 17.9% in 2026 from 2025.