The report behind every safe foundation

A soil report (geotechnical investigation report) describes the soil and groundwater conditions on your property and tells your structural engineer how to design a foundation for those conditions: bearing capacity, foundation type, seismic parameters, drainage, and grading criteria.

Most building departments in Northern California require one before they'll issue a permit for new construction, additions, ADUs, and hillside work. It's also simply how you avoid expensive surprises: cracked slabs, settling foundations, and failed retaining walls usually trace back to soil conditions nobody checked.

In most Northern California jurisdictions, yes. A detached ADU is new construction and typically requires a geotechnical report for permit approval. Requirements vary by city and by site conditions, so send us your address and we'll confirm what your building department requires before you spend anything.

It depends on the project size, site access, the number of borings required, and your jurisdiction's requirements. A simple ADU or addition costs considerably less than a hillside custom home in a seismic hazard zone.

We provide fixed-price quotes, usually the same day you ask, so there are no surprises. Request a free quote and you'll have a number within 24 hours.

We guarantee a 4-week project turnaround from field work to your finished, PE-stamped report. Quotes and proposals go out within 24 hours, usually the same day. If your permit timeline is tight, call us and we'll tell you honestly what's possible.

Our crew visits your property and drills borings or excavates test pits, typically a few hours of work for a residential lot. We log the soil profile layer by layer, note any groundwater, and collect samples. The samples then go to our in-house laboratory for testing per ASTM and AASHTO standards. You don't need to do anything to prepare beyond providing access to the site.

During an earthquake, loose, water-saturated soil can temporarily lose its strength and behave like a liquid. That's liquefaction, and it can cause structures to settle or tilt. The State of California maps Seismic Hazard Zones where this risk exists, and if your property falls inside one, your building department will require a site-specific liquefaction evaluation before issuing a permit. We perform Cone Penetration Testing (CPT) per ASTM D5778 and are permitted to advance soundings to 50 feet below grade for liquefaction analysis. We can check your parcel against the hazard maps when you request a quote.

A percolation (perc) test measures how quickly water drains through your soil: specifically, the time it takes for the water level in a test hole to drop one inch. County health departments require perc results before approving a septic system or leach field, and the data also informs stormwater and drainage design.

Whenever soil is placed as fill (under a building pad, behind a retaining wall, in a utility trench) it has to be compacted to the density specified in the grading plan, or it will settle later. We test the fill and backfill in the field as it's placed, using approved nuclear density gauges per ASTM D6938, and issue a final compaction report the building department uses to sign off your grading.

Yes. Every report is signed and stamped by a licensed Professional Engineer and formatted to the requirements of your specific jurisdiction. We maintain a 100% building-compliance record, and if a plan checker has questions, we respond directly. That follow-through is included.

It happens all the time: an addition grows, a footing foundation becomes piers, or the footprint shifts on the lot. We update and re-issue reports to match the new design, and because we already know your soil, revisions are fast. Just send us the updated plans.

If you want us to, absolutely. We offer foundation plan review, foundation inspection, pier-drilling observation, drainage and grading inspection, crushed-rock inspection, construction meetings, and final inspection letters, plus immediate telephone consultation whenever questions come up during construction.