Home Additions in Oak Park, scoped line by line
Home additions in Oak Park, IL — room additions, second stories, and in-law suites tied into your existing home by one accountable OnSite team. Your phone estimate is free; call (773) 900-7007.
Foundation, framing, and roofline tied cleanly into the existing home
Plumbing, electrical, and HVAC extended and balanced to the new space
Permits, inspections, and structural coordination handled for you
One accountable team from footing to final finish
Scoped, priced, approved — then built.
Send photos
Text us a couple of photos of what you're looking at. That's enough to start.
Walkthrough
A Zoom walkthrough of the space — it waives the $149 in-person written estimate.
Line-item estimate
A sectioned estimate with every line priced. You approve every line before any crew arrives.
The build
Our crews run the sequence — demo to punch list — and you sign off on the finished work.
- 01Foundation
- 02Framing
- 03Mechanicals
- 04Roofing
- 05Finishes
Each pass lands in your estimate as its own priced section — nothing hides in a lump sum.
Get your home additions estimate
Your phone and text estimate is free. An in-person written estimate is $149 — a Zoom walkthrough waives it. On hourly (time-and-materials) jobs, a $129 fee applies per material run. Tell us about the project and we’ll come back with a clear, line-item scope.
The home additions estimate, sectioned
- Foundation
- Framing
- Mechanicals
- Roofing
- Finishes
Every line priced. No lump sums.
Itemized · you approve every lineHome Additions in Oak Park — common questions
How much does a home addition cost in Oak Park?
We scope the foundation, framing, mechanicals, and finishes for your Oak Park, IL addition line by line so the estimate reflects your real footprint, not a per-square-foot average.
Can you match the addition to my existing house?
Yes — we match the roofline, siding, and trim so the addition reads as part of the original house, not a bolt-on.
Do I get a written, line-item estimate for home additions?
Yes — you get a sectioned, itemized estimate before any commitment, so you see exactly what each part of the work costs. No lump sums, no surprise change orders.
Are OnSite crews licensed and insured?
Yes. Every OnSite crew is insured, bonded, and background-checked, and one accountable team stays with your project from the first estimate to the final walkthrough.
Do you offer financing?
Yes — financing is available through licensed lending partners, so you can spread the cost over time. It's optional and there's no obligation; we can set it up once your estimate is ready.
Is the estimate really free?
Yes. Your estimate is free and there's no obligation — we scope and price the work up front so you can decide with the full picture in hand.
More work we take on in Oak Park
Terms & disclosures — Illinois
OnSite General Contracting is licensed and insured to perform work in Illinois. Estimates are provided under the Illinois Home Repair and Remodeling Act.
- Illinois Home Repair and Remodeling Act: a written contract is provided for projects over $1,000.
- Consumers receive the "Home Repair: Know Your Consumer Rights" pamphlet before work begins.
- Right to cancel within 3 business days for eligible home-solicitation sales.