A new-home foundation dig runs $1,500 to $10,000 and a basement dig $10,000 to $30,000 in HomeGuide's national 2026 figures. In Chicago, soft lake clay, high groundwater and neighbors a few feet away shape every foundation job.
Each dollar figure below is a national range published by HomeGuide, and none of them is a quote from us. Chicago blue clay, alley access, buried debris from old buildings and the haul to a dump site are what really set the cost of a job here. We read every HomeGuide page used here in October 2026.
What does foundation excavation cost for a new house in Chicago?
Foundation excavation for a new house in Chicago follows HomeGuide's national $1,500 to $10,000, with $20,000 or more for a large foundation in rocky ground, boulders or heavy clay. The dig is only part of it. A whole unfinished basement foundation is $70,000 to $100,000 on HomeGuide's foundation page.
What does basement excavation cost for new construction around Chicago?
Basement excavation for new construction costs $10,000 to $30,000 in HomeGuide's basement section, usually over 2 to 4 days. An 8 to 9 foot dig in normal soil is $10,000 to $20,000, and difficult or rocky ground $30,000 to $50,000 or more. HomeGuide's project table lists less, but the basement section is the one that fits. On a city teardown, removing the old basement is extra.
Can an old Chicago basement be dug out deeper, or a crawl space turned into a basement?
Digging an old Chicago basement out deeper is common in short-basement bungalows and two-flats, but it is structural work. For the dig alone, HomeGuide prices a basement under an existing crawl-space house at $20,000 to $45,000 or more. An engineer, a permit and underpinning by a foundation contractor are required, and a licensed general contractor runs the job in Chicago.
What does it cost to excavate around the foundation for waterproofing or repair?
Excavating around the foundation of an existing house costs $5,000 to $15,000, or $100 to $250 a linear foot, by HomeGuide's figures, and exterior waterproofing $6,000 to $18,000. Old brick and stone foundations under Chicago bungalows and two-flats are where we do most of it.
How far out from a basement wall do you dig on a tight Chicago lot?
On a tight Chicago lot, we dig about two to three feet out from the basement wall, enough for the crew, and shore the dig when a neighbor's house or walk is close. In soft clay, deep excavations need a protective system, never a vertical cut. Depth comes from the repair company's or engineer's plan.
Can you dig next to an old brick foundation without damaging it?
Yes, digging next to an old brick foundation without damaging it means short sections, no bucket on the wall, hand digging at the brick and quick backfill. Old soft brick and lime mortar walls lose support fast when the soil comes away, so we never leave a long stretch open.
How deep do footings go in Chicago?
Footing depth in Chicago is set by the building code and the engineer's plans, and footings must sit below the frost line on firm soil. On soft clay, footings may also need to be wider or deeper than the minimum. The plans and the inspector confirm the number for your project.
What does backfill around a new basement cost in Chicago?
Backfill around a new basement is usually part of the excavation price, and extra backfill runs $5 to $25 a cubic yard by HomeGuide's trenching page. Against a new basement wall, clean granular backfill drains and settles far less than the wet clay that came out of the hole.
Who is responsible when my foundation cracks after the excavation next door on a tight city lot?
If your foundation cracked after excavation next door, who is responsible depends on the cause, which an engineer has to judge. Photograph and measure the crack right away, with dates, and notify the neighbor, the contractor and the city in writing. On tight Chicago lots, photos of your walls before a neighbor's dig help most. This is general information about Illinois, not legal advice.
What does excavating for a walkout or outside basement entrance cost?
HomeGuide gives no figure for a walkout or an outside basement entrance. The digging is similar to excavating along a foundation, $100 to $250 a linear foot, and cutting the wall needs a structural design and a permit. A Chicago basement stairwell also needs a drain at the bottom so storm water does not run straight into the basement.
For a number on your own Chicago-area property, call or text (872) 201-3760. We look at the lot, then send the scope and the price in writing.