Seattle · King County
Excavation Contractor in Seattle, WA
Foundation digs, footings, utility trenches and building pads in Seattle, dug to spec by an owner-operated crew with its own excavators and dump trucks. Serving Lake City, Wedgwood, Maple Leaf and Northgate and the rest of Seattle.
What the ground is like for excavation in Seattle
Hills and ridges between Puget Sound and Lake Washington, with steep slopes and ravines through many neighborhoods. That shapes every excavation job here: where the machine can sit, how trucks get in and out, and where the spoil goes before it is hauled away.
Glacial till and outwash across most of the city, with landslide-prone slopes and soft fill in some lowlands. On a Seattle foundation that decides how deep we go to reach bearing soil, whether unsuitable material has to be over-excavated and replaced with compacted structural fill, and how we keep water out of the hole while forms go in.
Thornton Creek, Piper's Creek, the Sound and lake shorelines carry critical-area rules, and Seattle maps Environmentally Critical Areas for steep slopes and landslide-prone ground. If your footprint, trench or driveway lands near any of that, the excavation plan has to respect the buffer, and erosion control goes in before the first bucket.
Common excavation projects in Seattle
New home and ADU foundations
Footprints for new houses, ADUs and garages on infill and teardown lots around Lake City and Wedgwood, dug to the elevations on your plans and ready for forms.
Hillside cuts and daylight basements
Excavation on sloped Seattle lots, with spoil hauled off as it is dug instead of stockpiled on the slope, and temporary erosion control in place first.
Over-excavation and structural fill
Where Seattle ground is soft, we dig out the unsuitable material and place compacted structural fill in lifts so the footing bears on something solid.
Utility and water line trenches
Trenches for water, power, sewer and gas service from the street to the house or shop, backfilled and compacted, anywhere from Maple Leaf to the edge of Seattle.
Tight-access digs
Compact excavators for narrow side yards and alley-access lots in Seattle, with mats down to protect the driveway and the neighbors' property.
What our excavation work in Seattle covers
- Foundation Excavation
- Utility Trenching
- Construction Access Roads
- Building & Equipment Pads
- Rough & Finish Grading
- Spoil Haul-Off
Permits & Rules
Excavation permits and utility locates in Seattle
Inside city limits, the Seattle Department of Construction and Inspections (SDCI) handles building and grading permits. Properties outside city limits fall under the King County Department of Local Services. Foundation excavation is usually covered by the building permit, while grading or fill over set volumes, or any work in a critical area, can need its own approval.
Before any digging, Washington law requires a utility locate through 811 at least two business days ahead. We place that call on every job, and we pothole near marked lines instead of trusting paint alone.
Cost & Timing
What affects the cost of excavation in Seattle
We do not publish flat prices because no two Seattle sites are the same. These are the things that move the number most here.
Slope and access
Steep Seattle lots take smaller machines, more careful staging and sometimes engineering, which adds time compared with flat, open ground.
Tight lots
Narrow side yards and alley access in Seattle mean compact equipment and shorter truck loads. We plan it so it costs less than it could.
Soft ground
Where Seattle soils are soft or wet, over-excavation, fabric and imported rock are often part of the job, and we price that in up front.
Buffers and permits
Work near Seattle's rivers, creeks, lakes or shoreline can need permits and limits on where machines go. That affects scope and schedule more than price.
Haul-off and disposal
How much material leaves the site, and what it is, drives cost. Our own trucks keep that predictable on Seattle jobs.
When to schedule excavation in Seattle
Excavation in Seattle goes best in the drier months, when soil compacts properly and trenches stay open. Wet-season work is doable with erosion control and the right material, and we plan for it in the quote.
Seattle's till soils hold water through the winter, which is when drainage problems show up. That is a good time to see where water goes, and the dry season is the time to fix it.
Where We Work
Excavation across Seattle
In Seattle, DirtRaptor mostly works the north end, from Lake City and Wedgwood to Greenwood and Ballard. Seattle lots are tight, access is often by alley, and the city has detailed rules for trees and steep slopes.
We dig foundations, ADU and garage footprints, septic and utility trenches, and building pads across Lake City, Wedgwood, Maple Leaf, Northgate, Greenwood, Ballard, View Ridge and Magnolia. Craftsman and mid-century homes on small lots, with a lot of ADU, townhome and redevelopment work.
Our trucks run in and out on I-5, SR 99, SR 522 (Lake City Way) and NE 125th St, so spoil haul-off and fill delivery happen on our schedule instead of a subcontractor's.
We also do excavation nearby in Kirkland, Shoreline, Lake Forest Park and Kenmore. See everything we do in Seattle, read our full guide to excavation, or browse all service areas.
Why DirtRaptor
Why Seattle owners call us for excavation
Owner on the machine
On Seattle jobs you talk to the person who walks the site, writes the quote and runs the equipment.
Trees and dirt, one crew
If trees are in the way of your Seattle project, we take them down ourselves instead of waiting on a separate tree service.
Our own trucks
Haul-off and deliveries run on our schedule along I-5 and SR 99, not a subcontractor's.
Built for slopes
We plan machine placement, drainage and erosion control for Seattle's sloped ground before we start.
How an excavation job runs
- 01
Site Walk & Utility Locates
- 02
Layout, Staking & Access
- 03
Excavation & Spoil Management
- 04
Backfill, Compaction & Inspection
Real Jobs
Recent DirtRaptor work near Seattle
Demolition · Edmonds, WA
Driveway Removal & Concrete Prep
Tearing out an old blacktop driveway and prepping the ground for a new concrete pour — broken material hauled off, base left clean and ready.
Demolition · Everett, WA
Condemned 100-Year-Old Shed Teardown
A 100-year-old shed, condemned and unsafe, brought down and hauled off — the site left graded flat and clean.
Questions
Excavation Contractor in Seattle: FAQs
What kind of soil will you hit digging in Seattle?
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Glacial till and outwash across most of the city, with landslide-prone slopes and soft fill in some lowlands. We read the ground on the site walk and spell out in the quote how footing depth, over-excavation and imported fill are handled, so there is no surprise invoice.
Who issues excavation and grading permits in Seattle?
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Inside city limits it is the Seattle Department of Construction and Inspections (SDCI). Outside them it is the King County Department of Local Services. We confirm which applies to your parcel before quoting and flag anything that needs extra review, like a stream buffer or steep slope.
Can your trucks and excavator get onto my Seattle site?
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Almost always. We run compact and full-size tracked excavators and size the machine to the access. On tight lots we protect driveways and lawns with mats and stage trucks so the street stays open.
How much does excavation cost in Seattle?
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It depends on the site, so we quote after a free site walk rather than guessing on the phone. The biggest drivers in Seattle are usually slope and access, tight lots, soft ground. You get a written number with inclusions and exclusions spelled out.
When is the best time to schedule excavation in Seattle?
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Excavation in Seattle goes best in the drier months, when soil compacts properly and trenches stay open. Wet-season work is doable with erosion control and the right material, and we plan for it in the quote.
Can you work on a tight Seattle lot with alley access?
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Yes. Compact tracked machines and our own trucks let us dig, demo and haul off from alley access, with the alley protected and kept open as much as possible.
Do you handle site prep for ADUs in Seattle?
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Yes. ADU site prep usually includes small demolition, tree work, excavation for the foundation and utility trenching. We do it all with one crew.
Do you pour the concrete too?
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We excavate, prep and compact to spec, and coordinate directly with your concrete contractor on grades and timing. Confirming who is pouring early avoids the most common scheduling gap on residential builds.
Ready for a real number in Seattle?
Send the address and a few photos. We walk the site for free and come back with a written quote.
