How much does Earthquake retrofit cost?

People who’ve experienced a major earthquake know how scary it can be—and after the shaking stops and the dust settles, many wish they would’ve prepared better. 

If you’re lucky, you had a few broken dishes and cracks in the walls. Other homeowners, however, have been considerably less fortunate. In the Southern California areas of Los Angeles or Northridge and Bay Area cities like San Francisco and Loma Prieta, the damage has been devastating, with homes sliding off their foundations and walls collapsing. 

Earthquake retrofitting can help you prepare for the next Big One, even if you’re not on the West Coast. Adding earthquake resistance is especially important for older homes built pre-1960, before building codes required single-family homes to be protected from earthquake damage. 

Earthquake retrofitting requires the knowledge, skills, and tools of a specialized earthquake retrofit professional. So whether you’re in Seattle, on the Oregon Coast, or in Montana or Nevada (where some of the largest earthquakes in the US have occurred over the last 100 years), this guide will help you understand how to prepare your home from structural damage associated with seismic events.  

The average cost of earthquake retrofitting a conventional home with a concrete slab foundation or raised perimeter foundation runs $3,200–7,500, on average, including material and labor costs. Keep in mind that these numbers are averages, and costs can be less or significantly more.

Bolting. To seismically retrofit a house, pros will often bolt the wooden mudsill (the boards that sit directly on the foundation and attach to the home’s walls and floor joists) to the foundation itself, whether it’s a concrete slab foundation or a raised perimeter concrete foundation. This prevents the home from sliding off its foundation during earthquakes.  

Reinforcing. Some houses with raised foundations have “cripple walls” (short walls between the foundation and the first floor joists) that conceal a crawl space beneath the home. Retrofitting these houses involves attaching plywood sheathing to the cripple walls, turning them into “shear walls” with added lateral strength that don’t collapse in an earthquake. 

Bracing. Pros will add special steel brackets that attach the cripple walls to the floor joists to help with stability in wood-frame houses.

On the low end, a single-story home that only requires foundation bolting might cost $1,000–3,000 to retrofit. On the high end, retrofitting a multiple-story home built over a garage (called a soft story because of the large openings) or on a hillside can easily cost $15,000 or more. For mobile homes, earthquake bracing systems can often be installed for under $5,000. 

Before moving ahead, get a seismic inspection from a retrofitting or foundation repair company at an average cost of $100–400. 

Factors that can affect the total cost of seismically retrofitting a home include the following. 

These tactics may save money on seismic retrofitting or cover earthquake damage.  

How much does earthquake retrofitting cost?

Seismically retrofitting a house costs $3,200–7,500, on average, and can provide peace of mind to homeowners living in earthquake-prone regions. If a large quake occurs, homes that haven’t been retrofitted can slip from their foundations, causing irreparable damage. 

Does earthquake retrofit increase home value?

Earthquake retrofits increased home resale value by nearly 10% in California, which was substantially more than the cost of the retrofit, according to a 2020 study from the University of Colorado Boulder. 

How do you retrofit a house for earthquakes?

The most common retrofitting jobs involve bolting and bracing the home’s wooden structure to its foundation and reinforcing “cripple walls” for added strength. A good first step is to hire a professional seismic retrofitting or foundation repair company to assess your home and recommend the best course of action for your home’s size, age, and other structural attributes (average cost $100–400). Moving ahead with a retrofit costs an average of $3,200–7,500. 

Find an earthquake retrofit professional in your area.

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