When is a Geotechnical (Soils) Report Required?


The following types of projects are provided to help the Applicant determine whether their project will require submittal of a Geotechnical Investigation report or Soils Report. Soils Reports are typically not required for single story non-habitable structures. Please note that the Planning Division reserves the right to require soils reports for projects that are not listed below. The County Geologist or a Registered Civil Engineer will make the final determination whether a geotechnical investigation is required for a project.

A Geotechnical (Soils) Report is required for the following types of projects:

1. New single-family buildings, multi-family buildings, detached Accessory Dwelling Units, or habitable accessory buildings.
2. Commercial buildings, industrial buildings, or critical facilities.
3. All two (or more) story buildings whether habitable or non-habitable, regardless of square footage.
4. A habitable or non-habitable building which includes a mezzanine.
5. Additions to any of the above which are: located on slopes greater than 20%; located on fill; located in an area of County GIS mapped expansive soils or potential liquefaction (mapped as moderate to very high); or located in a FEMA designated flood plain, floodway or a coastal high hazard zone.
6. Additions to single-family buildings, multi-family buildings, or habitable accessory buildings greater than 500 square feet require a soils report. Single-story additions, two-story additions, and second story additions of 500 square feet or less do not require a soils report, and may also be exempted from addressing mapped expansive soils and/or potential liquefaction (mapped as moderate to very high).
7. Non-habitable buildings over 1,000 square feet.
8. Additions to a commercial buildings, industrial buildings, or critical facilities greater than 250 square feet.
9. Modification, reconstruction or replacement of 65% the major structural components consisting of the foundation, floor framing, exterior wall framing, and roof framing of an existing habitable structure within any consecutive five-year period, or modification, reconstruction or replacement of 50% of the major structural components of an existing critical structure or facility, as defined by ASCE/SEI Standards, within any consecutive five-year period, whether the work is done at one time or as the sum of multiple projects.
10. The addition of habitable space to any building, where the addition increases the habitable space by more than 50% over the existing habitable space, measured in square feet.
11. Additions of any size to a building that is located on a coastal bluff, dune, or in the coastal hazard area, that extends the existing building in a seaward direction.
12. Installation of a new foundation for a habitable building.
13 The repair, replacement, or upgrade of an existing foundation of a habitable building that affects more than 50% of the foundation (measured in linear feet for perimeter foundations, square feet for slab foundations, or 50% of the total number of piers), or an addition to an existing foundation that adds more than 50% of the original foundation area, whether the work is performed at one time or as the sum of multiple projects during the life of the building.
14. Any change of use from non-habitable to habitable use, according to the definition of “habitable” found in Section 16.10.040 of the Santa Cruz County Code, or a change of use from any noncritical facility to a critical facility.
15. Any alteration of any building posted “Unsafe to Occupy” due to geologic hazards.
16. Retaining walls greater than 4 feet in height, retaining walls that function as a part of a landslide repair, sea walls, or gravity walls.
17. Bridges or water tanks greater than 10,000 gallons.
18 Land divisions or coastal protection structures.
19. Above ground commercial storage facilities for hazardous or flammable materials.
20. Proposed building sites or access roadways located on property having undocumented or unpermitted grading (such as log landings, logging roads or prior unauthorized grading).
21. Grading with cuts or fills over three feet in height located within five feet (horizontally) of a property line or grading that has the potential to cause instability or other grading related impacts to adjacent property.
22. Access driveways or roadways that include fill greater than 2 feet.
23. Grading on slopes greater than 20%.
24. Creation of cut or fill slopes five feet or greater in height related to slope stabilization, landslide repairs, or streambank protection.
25. Grading activities where there is evidence of high groundwater or spring activity.
26. Any portion of development located within a FEMA floodplain or floodway.
27. Any project or structure required by the current California Building Code to have a geotechnical report.
28. Any other project deemed by Planning Division Civil Engineering staff or the County Geologist that a geotechnical report is required to ensure the integrity of the proposed work.