Accessory tool shed on hillside in Los Angeles

[Michael Mueller]

What are the requirements to build a tool shed less than 120 sqft in a hillside backyard in Los Angeles?

I gather that an accessory building less than 120 sqft is exempt from building permit, but must still be constructed in accordance with the building code including foundation and slope setbacks and other hillside construction requirements. I also read that "buildings and structures on or adjacent to slopes steeper than 3 horizontal to 1 vertical" need H/2 setback from an upslope. The backyard does not provide space for that setback, and the homeowner wants to build the tool shed on the slope.

I read that "Recommendations by a licensed geotechnical engineer may be used if a foundation investigation report addressing the reduced setback has been approved by the Department."

What is the process of getting this approval? Can this approval be applied for without getting a permit for the shed (which is otherwise not required)?