Earthquake safety is an important component of home improvement. It can save a lot of money if you have it constructed properly. In fact, some of the most expensive remodels happen when they are not completed properly. You also need to make sure that your floor plans are earthquake safe as well.
It is also a good idea to have a licensed engineer evaluate your foundation and do a preliminary inspection and report on whether you need to add any seismic features to your building or if you can simply install earthquake safety devices on existing floor joists or on other appropriate locations. They should also check the foundation of your building for loose timbers, under-sinking of the floor, etc. This will be much cheaper than having to replace the entire foundation.
During the initial review, they will check for your willingness to invest in the future. They may recommend earthquake safety enhancements like seismic retrofitting.
Besides the things mentioned above, it is important to have fire safety equipment installed such as sprinkler systems and smoke detectors. The existing wiring should be checked for connections, etc.
After the safety review, you will need to inspect the building to make sure that there are no weak spots in the foundation. If you have structural steel built to your house, then you should have this used in a way that it can withstand the force of a major earthquake.
If the foundation is built for a subfloor then you should be careful to make sure that the level is higher than the actual foundation. You can buy leveling kits that can do this for you. It will allow you to put a new floor on top of the old floor to raise the building.
When you consider a basement, you should check that it does not lead away from the center of the house to a point where it meets a ground fault. This will give the building more potential for damage by earthquakes.
Seismic retrofitting is the most important seismic design element to take into account for earthquake safety. You should never build your house without taking this seriously. A good architect can help you with this.