Bolting homes to foundations and other structural improvements cost relatively little, but mean less damage and more homes left standing after the inevitable Big One.
Seven small earthquakes off the coast of Oregon caused no damage, but they are a reminder of the seismic potential of the faults underneath Oregon and potential for significant damage to tens of thousands of homes, according to retrofit experts.
Seismic risk is greatest on the West Coast: California lies on the San Andreas fault, and Western Oregon and Portland on the volatile Cascadia Subduction Zone, which experiences a major earthquake every few hundred years. The last major earthquake along the Subduction Zone was in the year 1700.
While public health experts wisely counsel about the need to have an emergency preparedness kit, home retrofit experts are clear on the benefits of relatively simple and affordable home seismic upgrades. Usually costing just a few thousand dollars, a seismic retrofit can mean one’s home is left standing and connected to its foundation, rather than being a total loss that must be torn down and abandoned post-quake.
“Seismic upgrades provide a proven way to ‘harden’ a home and give it stability during the violent shaking of an earthquake,” said Stephanie Swanson, Enhabit’s vice president of communications. “The retrofit is relatively affordable and gives families peace of mind that home will be safer and less damaged.”
For example, the city of Portland has about 105,000 older, unreinforced homes that are particularly vulnerable to major damage during an earthquake. Tens of thousands of homes across the state are also vulnerable. Reinforcing and upgrading a home includes bolting the house to its foundation, reinforcing the ‘cripple wall’ (the short wall between the first floor and the foundation), and shoring up the posts and beams that bear weight under a home. Enhabit, the state’s largest home performance provider, now provides seismic retrofits through qualified contractors as part of its services.
A typical seismic retrofit costs is around $6,000 to $8,000, work that can be easily financed through the nonprofit’s financing partners who offer low-interest loans to homeowners. Additionally, homeowners find that coupling a seismic upgrade with weatherization provides additional benefits, since that work also happens in the walls and wires of a home and can be done conveniently while a seismic upgrade is taking place.
“This is an investment in safety that will pay back in a big way should we experience a major—or even a relatively minor—earthquake. If a home is knocked off its foundation, it’s not only unsafe, it’s generally considered a total loss,” said Swanson.