Foundation, Basement and Site Excavation Services
Excavation covers much more than moving dirt. The scope depends on the building, the soils, and how much room there is to work. Typical excavation work on Bay Area projects includes:
Basement and Below-Grade Excavation
Digging for basements, podium garages, elevator pits, and below-grade rooms on tight urban lots. These excavations usually run right up to the property line, so they’re planned together with shoring, underpinning, and the foundation design.
Mass Excavation
Bulk removal of soil to reach subgrade across a building footprint or site, with loading and haul-off sequenced to keep trucks moving and the site safe.
Foundation and Footing Excavation
Excavation for spread footings, grade beams, mat foundations, and pile caps, cut to the lines and elevations on the plans and prepared for inspection before concrete work begins.
Hillside and Slope Excavation
Cuts into sloping ground for new homes, additions, retaining walls, and driveways. These sites call for careful benching, drainage control, and access planning, often alongside soil nails, retaining walls, or helical piles.
Trench Excavation for Utilities
Trenching for water, sewer, storm drain, and dry utilities, with trench protection installed as required. See Utility Installation for more on underground work.
Over-Excavation and Recompaction
Removing unsuitable soil below a foundation or slab and replacing it with properly placed and compacted fill, when the geotechnical engineer calls for it.
Haul-Off and Material Management
Loading, trucking, and disposal or reuse of excavated soil. Where soil needs testing or special handling, we work with the project’s environmental consultant on how it’s managed.
What Shapes an Excavation in the Bay Area
No two Bay Area excavations are alike. Before we dig, we look at the factors that drive cost, schedule, and risk:
- Soils and groundwater. Fill and bay mud near the shoreline can be soft and wet. Dune sand in western San Francisco caves easily. Hillside sites in Marin and the East Bay hills can hit weathered rock, clay, or loose slope deposits. The geotechnical report tells us what to expect, and we plan equipment and sequencing around it.
- Adjacent structures. On lot-line sites, the excavation can’t undermine neighboring foundations. That often means shoring or underpinning has to go in first, and digging follows in stages.
- Existing utilities. California law requires an 811 ticket before digging, and older neighborhoods often have abandoned or poorly mapped lines. Potholing and careful hand-digging near known utilities protect both the schedule and the crew.
- Access and staging. Narrow streets, steep driveways, and limited parking control what equipment fits and how trucks get in and out. Haul routes and street use often need to be planned with the local jurisdiction.
- Worker safety. Cal/OSHA generally requires a protective system for trenches and excavations 5 feet or deeper that workers will enter, unless the excavation is entirely in stable rock. Sloping, benching, shoring, and trench boxes are chosen to fit the site.
Our Excavation Process
- Preconstruction review. We review the plans, geotechnical report, survey, and utility information, and identify where shoring, underpinning, or dewatering may be needed.
- Planning and coordination. We sequence demolition, shoring, excavation, and haul-off, and work with the project team on submittals, neighbor notifications, and permit conditions.
- Utility locating. We open an 811 ticket, review available records, and pothole where needed before excavating near utilities.
- Excavation. We dig in lifts and in sequence with the shoring, keeping cut slopes, benches, and trench protection in place as required.
- Subgrade preparation. We bring the bottom of the excavation to grade, compact or over-excavate as the geotechnical engineer directs, and get it ready for inspection.
- Handoff. We turn over a clean, stable excavation ready for foundations, or move straight into concrete work and utilities ourselves.
One Contractor From Demolition to Foundation
Excavation is where several scopes meet. The building has to come down, the shoring has to go in, the utilities have to be found and rerouted, and the foundation crew needs a clean subgrade on schedule. LVI Engineering is a general engineering contractor that handles demolition, excavation, shoring, helical piles, grading, utility installation, and concrete work. Keeping those scopes with one team means fewer handoffs and fewer gaps between trades.
We can also support preconstruction, design-build, and design-build-assist projects, helping owners and design teams compare excavation and shoring approaches before drawings are final.
Safety comes first on every dig. LVI sets a goal of a zero incident rate, and our employees are trained to plan their work in advance and put the right controls in place before work starts.
Where We Excavate
We work throughout the region, including San Francisco, Marin County, the East Bay, Sonoma, Napa, Sacramento, and Monterey. See all of our service areas.
Excavation FAQs
Do I need shoring for my excavation?
Often, yes. Cal/OSHA generally requires a protective system for excavations 5 feet or deeper that workers will enter, and excavations near property lines or existing foundations often need engineered shoring at shallower depths. Your geotechnical and structural engineers make the final call, and we can build to their design.
How long does a basement excavation take?
It depends on the volume of soil, how the shoring is staged, soil conditions, truck access, and any work-hour limits. Once we’ve reviewed the plans and geotechnical report, we can give you a schedule for your specific site.
What happens to the excavated soil?
Clean soil can sometimes be reused on site or at another location. Other soil is hauled to an appropriate facility. If testing shows the soil needs special handling, we follow the plan set by the project’s environmental consultant.
Can you excavate on a steep or tight-access lot?
Yes. Hillside and tight-access sites are common in San Francisco, Marin, and the East Bay hills. We plan equipment, staging, and haul-off around the access you have, and coordinate with shoring or retaining work as needed.
Do you handle permits?
Permit responsibility depends on how the project is contracted. We work with owners, general contractors, and design teams on the excavation-related submittals and permit conditions for each job.
Request an Excavation Quote
Planning a basement, foundation, or site excavation in the Bay Area? Send us your plans, geotechnical report, and schedule, and we’ll put together an approach that fits the site.
Call the office at 415-599-9575, call Joe directly at 415-305-5034, or email joe@lviengineering.com.
LVI Engineering · 1485 Bayshore Blvd, Suite 320A, San Francisco, CA 94124
