If you aren't sure if your home is bolted to its foundation, crawl, stoop or walk under your home and take a peek. If it doesn't have a crawl space, look at the foundation connections in your garage, utility closet or other room with unfinished wall framing. Otherwise, you may have to remove a portion of the dry wall to inspect. If it's bolted in the garage, it's likely the rest of the home is bolted. Framing is typically bolted to the foundation at the sill, the lowest point in the wood frame.
Engineers recommend expansion bolts fastened into the sill plate at intervals of six feet or less.
Where you can't reach areas to bolt the foundation, you can use foundation brackets and anchors nailed to the mud sill and then bolted to the side of the foundation. To further protect against lateral movement, shore up unsupported cripple walls. It should be reinforced with shear walls-plywood properly installed on the inside, to prevent the wall from buckling and folding over on its foundation. Among the first images of damage from the Seattle area quake were crumbling masonry structures including the Washington state capitol building. Strengthening and repairing such structures requires the expertise of a mason or other likewise experienced contractor familiar with masonry and masonry strengthening materials.