It’s a big deal if you want to renovate your home in Pico-Robertson in specific or Los Angeles in general.
Because Southern California is prone to earthquakes, building codes are strict.
So you want to remodel your home? You will have to get permission from the city of Los Angeles. What does that entail? Among other things, it requires some loud smelly machine to show up with a crew of workers and to dig 50 feet below surface of your front yard and your back yard and take core samples every five feet.
With this information, the city can determine how strong of an earthquake your new building will be able to handle.
Wikipedia says: Soil liquefaction describes a phenomenon whereby a saturated soil substantially loses strength and stiffness in response to an applied stress, usually earthquake shaking or other sudden change in stress condition, causing it to behave like a liquid.