2026 Pricing · Will & DuPage County
Almost nobody in this market publishes pricing. We think that is backwards. You should see realistic numbers before anyone sits at your kitchen table, so here they are: most full basement finishing projects in Will and DuPage County land between $55 and $145 per square foot in 2026.
That means a typical 1,000 square foot basement runs roughly $55,000 to $145,000 depending on what you build. The tiers below show where different scopes usually land. Every ONIT quote is itemized line by line, so you can see exactly which choices move your number and adjust before we start.
$55–$75 / sq ft
Drywall, LVP flooring, recessed lighting, paint. The clean, bright starting point.
$75–$100 / sq ft
Adds a full or half bathroom, better flooring and trim, and a storage plan.
$95–$125 / sq ft
Custom wet bar, media wall or theater area, designer lighting, upgraded finishes throughout.
$120–$145+ / sq ft
Full bar, dedicated theater, wine room, gym, spa bath, cigar lounge, or golf sim. Fully custom.
Bathrooms. The single biggest swing. Using an existing rough-in might add $12,000 to $20,000; starting from nothing with an ejector system adds more. It is also the upgrade most worth making.
The bar. A dry bar with stock cabinets is a modest line item. A custom wet bar with stone counters and refrigeration typically runs $15,000 to $40,000 within a project.
Ceilings and lighting. Drywall ceilings with layered recessed lighting cost more than a drop grid and are worth every dollar in how the space feels.
Specialty rooms. Theaters, wine cellars, cigar lounges, and golf sims each carry their own equipment and mechanical costs. Their pages on this site give honest per-room ranges.
Every town we serve requires permits for basement finishing that touches electrical, plumbing, or bedrooms. Bedrooms require egress windows. Furnace rooms need clearances and combustion air. None of this is a problem, it is just work that has to be planned and inspected, and it is included in every ONIT project and every ONIT quote.
Most full basement finishing projects in Will and DuPage County run 55 to 145 dollars per square foot. A 1,000 square foot basement typically lands between 55,000 and 145,000 dollars depending on scope and finish level. Bathrooms, bars, and theaters push toward the upper half.
Scope. An open lounge with LVP flooring and recessed lighting sits near the bottom. Add a full bath, a custom wet bar, a theater, and high-end finishes and the same square footage can double in cost. The itemized quote shows exactly which choices drive your number.
Dramatically. Additions in this market commonly run 300 to 500 dollars per square foot because you are buying foundation, framing, and roof. Your basement already has all three.
Included. Our quotes cover design, permits, inspections, labor, and materials as line items, so there are no surprise add-ons at the end.
In this market, yes. Finished lower levels consistently return a meaningful share of their cost at resale and often make the difference in how fast a home sells, especially with a bathroom included.
Tell us about your basement and we will follow up within one business day to set up an in-home visit.