Digging a new home's foundation costs $1,500 to $10,000 on HomeGuide's 2026 national page, and can pass $20,000 in heavy clay, boulders or rock. Clark County homes are built on crawl spaces, basements and slabs, and wet soil shapes every dig.
We did not set the dollar figures on this page: they are national ranges from HomeGuide. In Clark County, wet-season clay, trees, slope, groundwater and haul distance are what push a real job up or down. Figures checked October 2026.
What is the foundation excavation cost for a new house?
HomeGuide's excavation page lists $1,500 to $10,000 for the foundation dig on a new home site, and more than $20,000 for large foundations in rocky soil, boulders or heavy clay. Concrete is separate: a crawl space foundation for 2,000 square feet runs $30,000 to $36,000 on HomeGuide's foundation page.
What does digging a basement cost?
In HomeGuide's basement section, digging a basement for a new home costs $10,000 to $30,000, typically over 2 to 4 days, and $30,000 to $50,000 or more where access is hard or the soil is rocky. For an 8 to 9 foot basement in ordinary soil, the dig runs $10,000 to $20,000. The page's project table lists $1,500 to $10,000; the basement section is the one to use. Pumping in a wet winter adds to the job.
Can a crawl space be dug out into a basement, or a basement deepened?
Yes, as a structural project with an engineer, underpinning and a permit. HomeGuide's figure for digging a new basement under a home with a crawl space is $20,000 to $45,000 or more, for the excavation alone. Groundwater in low areas can make it harder.
How much does excavating around a foundation for waterproofing cost?
Excavating around an existing foundation for waterproofing or repair runs $5,000 to $15,000, or $100 to $250 a linear foot, on HomeGuide's page. For a basement, the dig goes to the footing so the crew can seal the wall and lay a new drain.
How far from the foundation wall do you dig for repairs?
We dig far enough for the crew to work safely, usually two to three feet beyond the wall at the bottom, with the sides sloped or shored on a deep basement. Wet clay can slump without warning, so deep cuts are never left open longer than needed.
Can you dig alongside a foundation without damaging it?
Yes, with the right plan: short sections, no digging below the footing, hand work near the concrete and prompt backfill after inspection. In the rainy season we cover open trenches and pump them as needed so water does not pool at the wall.
How deep do footings need to go in Clark County?
Footings must go below the frost depth your building code sets and rest on firm, undisturbed soil, with the engineer's plans setting the size and any extra depth. We dig to the plans and the inspector's checks, and we do not guess. Soft or wet soil at the footing bottom has to be removed and replaced as the engineer directs.
What does backfill around a new foundation cost?
Most bids include backfill in the dig price. When more material is needed, HomeGuide's trenching page lists delivered backfill at $5 to $25 a cubic yard or $4 to $15 a ton. Around a crawl space or basement here, free-draining rock over a footing drain keeps groundwater off the wall.
My foundation cracked after the neighbor's excavation. Who is responsible?
Who is responsible for a crack or settling after excavation next door depends on the cause, which an engineer has to judge. Photograph and measure it right away, and notify the neighbor and their contractor in writing. Washington contractors must be registered with L&I and carry a bond, which can matter for a claim. This is general information, not legal advice.
What does a walkout basement door dig cost?
HomeGuide lists no price for a walkout. The dig is close to excavating around a foundation, $100 to $250 a linear foot, plus a wall opening designed by a structural engineer. On sloped Camas or Washougal lots, a walkout often comes with a retaining wall and an area drain at the door.
Tell us about your project and we will come look at the ground, then send the scope and the price in writing. Call or text (360) 276-9112.