Earthquake Resistance for Calif. Homes..Question

Based upon current earthquake standards…

What strength or size of an earthquake are calif. residential
houses built to resist?


To my understanding, construction is built to the prevailing codes and incorporates the elements for seismic/earthquake “resistance” as per approved plans, engineering etc. I’m not aware of a number that a building will not suffer damage based on a certain event on Richter or other scale.

Earthquake resistant structures and engineering seek to limit damage to building and loss of life from collapse or component failure… but at end of day, it’s a limiting factor.

I dug up a bookmark… gives some un-cited information as to what they “think” happens to building during such.

Having said that, as home/commercial inspector… I will bring to a buyers attention where I can see that a building is un-bolted to foundation or has a lack of any shear at cripple walls or re-enforcement as a courtesy and when visible. I do my best!

Also… and if you perform multi family and some commercial (and even if you don’t as some homes have it), becoming familiar with items like Soft Story/Floor construction, Moment Bracing for URM and such will go a long ways to help your customers, a bit outside of a “required” item, but important!

Another way to say what Tim said…In California, the state has been divided up into Zones, based on seismic shaking potential. Earthquake shaking hazards are calculated by projecting earthquake rates based on earthquake history and fault slip rates, the same data used for calculating earthquake probabilities. The state building codes dictate the siesmic loads you must design the building to resist depending on what zone your structure is located in. A house in a geologically active area will be designed to hold up to a larger earthquake than the same exact house in a less geologically active area. Even the same exact house built in the same Zone, in 2 different locations could be designed radically different based on different soil conditions that they are sitting on. So, there is no magic number that a house can stand up to, but each one is designed to withstand the forces it is likely to be subjected to based on a lot of things, but primarily seismic zone, and soil conditions.

Hi Vern!

Good info and welcome to the boards!