Basement finishing cost in Chicago, IL: what 52 permits declare

The median declared cost of basement finishing on Chicago building permits filed 2024–2026 is $30,000. Half of all permits fall between $15,000 and $50,000. The national sourced whole-project range on our basement finishing cost guide is $7,000–$23,000.

Median declared cost

$30,000

52 permits

Middle half

$15,000–$50,000

p25–p75

Full span after trimming

$1,500–$270,323

$500 floor, top 1% removed

How to read this

These figures are the project values applicants declared to the Chicago permitting office, which uses them to calculate permit fees. Declared values tend to sit below the final invoice, and jobs done without a permit are not counted at all. Read the median as a floor for a permitted basement finishing job in Chicago, then check it against the sourced national range and get local quotes.

Where the data comes from

Source: Chicago open-data portal, dataset ydr8-5enu. Filter: residential permits issued 2024-09-09 to 2026-09-09 whose description matcheswork_description like 'SCOPE:%' AND upper(work_description) like '%BASEMENT%' AND (upper(work_description) like '%FINISH%' OR upper(work_description) like '%REMODEL%') AND upper(work_description) not like '%ADDITION%' AND upper(work_description) not like '%NEW CONSTRUCTION%' AND upper(work_description) not like '%GUT%' AND upper(work_description) not like '%DIG%' AND upper(work_description) not like '%UNDERPIN%'. Compiled 2026-09-09. Full method on the methodology page; every cell is in the CSV download.