Earthquake or seismic retrofitting is the practice of reinforcing and stabilizing the existing structure of a house or building to make it more resistant to the effects of earthquake activity. Ground motion or soil failure are common results of a seismic event, and in areas at high seismic risk, like California and other western states, the need of earthquake retrofitting is recognized and required in many urban areas. In an earthquake, side-to-side forces and movement create the biggest damage. Different methods of retrofitting exist and are used accordingly to the type of structure and soil conditions.

Most houses in the United States are built with wood-framed structures, which is an advantage, since wood is lightweight and more flexible than masonry therefore one of the most earthquake-resistant materials. When the structure is properly designed, wood framing structures combined with masonry can be an effective construction technique for seismic areas. But the understructure of a house must always be properly built and secured to prevent dangers and damage to the rest of the house. In a typical residential retrofit, there are some basic techniques that can be used to reduce the effects of earthquake activity.