How Much Does an Earthquake Retrofit Cost in 2025?

Earthquake Retrofit Cost Factors

We can break down the cost of a seismic retrofit into two main categories: Labor and materials. 

Cost per Square Foot

On average, you’ll spend between $3 and $7 per square foot for a seismic retrofit. On the lower end, you can expect a simple universal foundation plate installation. On the higher end of the earthquake retrofit cost spectrum, you can expect more complicated work like building a cripple wall or installing plywood or shear walls.

Materials 

Materials make up roughly 30% of the total seismic retrofit cost. Common material expenses include:

• Foundation plates: $100–$120 per linear foot

• Foundation anchors: $50–$100 per anchor

• Foundation brackets: $25–$75 per bracket

• Gas shutoff valve: $100–$250

• Plywood: $10–$20 per sheet

• Wall bracing: $2–$10 per square foot

Location

You only need to consider a seismic retrofit if you live in an area prone to earthquakes, typically on the West Coast. Costs can vary depending on the city you live in.

Labor

Labor makes up anywhere from 60% to 90% of the total price of a retrofit. On average, you’ll spend 70% of the total on labor, or $2,000 to $8,000 for the average project.

The actual amount varies based on what your home needs. For example, if you only need bolting without plates or a new cripple wall, most of the price comes from labor. But if you need plates installed, a new knee wall, and sheathing, more money will go into the materials.

Seismic Retrofit Costs by Task

Bracing and bolting walls costs anywhere from $500 to $10,000 or more, depending on how it’s done. The methods vary depending on the architecture of your home. Let’s explore four common retrofit methods, as well as a fifth task that’s important for any seismic retrofit:

Anchoring a Mudsill

Anchoring a mudsill costs between $1,000 and $2,500. This process places anchor bolts through the mudsill—also called a sill plate—and into the stem or cripple wall. This technique is common in homes with brick foundations or crawl spaces and is meant to prevent the wall and mudsill from slipping off the foundation.

Cripple Shear Wall Bracing

Bracing cripple shear walls costs between $1,000 and $3,000. This process uses plywood sheathing and 2-by-4 blocking to reinforce the cripple wall. Cripple walls are short walls that close off the crawl space in your home. Older homes are prone to collapsing during earthquakes when they aren’t braced.

Cripple Wall Bolting

Bolting cripple walls costs between $1,000 and $3,000. Instead of anchoring to a mudsill, the crawl space walls are bolted to the floor above. This process still involves bracing cripple walls.

Universal Foundation Plate

Universal foundation plate (UFP) retrofitting costs between $500 and $3,000. The plates alone go for about $20 each. This is the most basic earthquake retrofit you can do to your home.

Earthquake Valve Installation 

Installing an earthquake gas shutoff valve costs around $200 to $500, with most homeowners paying around $350. The four preceding tasks involve methods of bracing and bolting, but this task is separate and often required for home sales. Some cities even require and charge for inspections.

Earthquake gas shutoff valves themselves run from $100 to $250, or $500 to $1,500 or more for commercial-grade earthquake valves.

Seismic Retrofit Costs by Foundation Type

The foundation type upon which your home sits can affect the overall earthquake retrofit cost. Slab foundations are the most affordable for retrofitting (as low as $1,000), while brick, post and pier, and wood foundations can all lead to a seismic retrofit cost of $10,000 or more.

Basement Foundation

Except for older homes, areas with a lot of seismic activity don’t commonly have basements. Homes built on a basement foundation cost between $3,000 and $5,000 to seismic retrofit. 

Materials for a basement foundation earthquake retrofit include plywood, bolts, and metal wood connectors. The contractor will anchor the house to the basement for optimal earthquake protection.

Brick Foundation

The average seismic retrofit cost for a brick foundation starts as low as $2,000 but can easily surpass $10,000 if the bricks and mortar are in poor condition. The brick must be mortared to the mudsill, which then must be anchored to the house. The project will require more labor and materials if the mortar isn't properly connected to the mudsill.

Footing and Stem Wall Foundation

Earthquake retrofitting a house with a footing and stem wall foundation costs between $3,500 and $7,200. A house with a footing and stem wall foundation uses a wood-framed base floor filled with concrete. Because a local foundation installation contractor must install foundation plates beneath this concrete floor, it could involve high labor costs.

Post and Pier Foundation 

An earthquake retrofit for a house on a post and pier foundation costs between $3,000 and $10,000 or more. A post and pier foundation is an older style of construction that uses spaced piers with posts attached to them. Instead of floor joists spanning the foundation (either to the mudsill or a stem or cripple wall), these regularly spaced posts hold up the home. Retrofitting a post and pier foundation requires tying the posts to the piers and then the house with T-straps or another anchoring material.

Slab Foundation

The earthquake retrofit cost for a home on a slab foundation can be as low as $1,000, though your expenses may reach $3,000. Houses built on slabs don’t have crawl spaces or cripple walls, meaning labor is minimal. The house merely needs to be anchored to the slab.

Wood Foundation

Retrofitting a house on a wood foundation is expensive, from $5,000 to $10,000 or more. Wood foundations aren’t ideal for seismic activity. If your home sits on a wood foundation in an earthquake-prone area, the contractor may recommend replacing portions or all of the foundation.

Seismic Retrofit Costs by House Type

In addition to the foundation, the house type can impact your overall earthquake retrofit costs. Below, we'll explore some more unique home types where retrofit costs may not align with the standard house type.

Mobile Home Earthquake Bracing Cost

An earthquake-resistant bracing or engineered tie-down system for a mobile home costs approximately $2,000 to $13,000. The systems use one of three methods:

• Primary support column (PSC) earthquake anchoring costs around $3,000–$9,000.

• An earthquake-resistant bracing system (ERBS) costs around $2,000–$4,000. These use anchors in the ground with tie-down straps.

• Pouring a slab foundation with footings runs around $5,000–$25,000. This isn't a common option but provides excellent protection.

Manufactured Homes Earthquake Retrofit Prices

Depending on the foundation type, manufacturers can use either a mobile home or a traditional home strategy. To use home methods for bracing, you'll need a foundation or basement.

• Foundation installation costs around $5,000–$15,000.

• Installing a basement costs around $50,000–$150,000.

Soft Story Retrofit Cost

Retrofitting a soft story costs anywhere from $10,000 to $80,000. For apartment buildings, property owners can expect to pay $80,000 to $350,000 or more.

A soft story is any multistory building with a large opening where a shear wall for structural support would normally go. The most common example for residential homes is a second story over a garage or carport. You’ll need to reinforce the area around the garage doors and often the adjoining walls to carry more weight and make them more rigid.

Hillside House

Retrofitting a house on a hillside for seismic activity can increase the average earthquake retrofit price. Expect to pay anywhere from $5,000 to $10,000. Homes built into a hillside tend to have weaker support structures that can't withstand seismic activity, as well as a house built onto a flat area.

Does an Earthquake Retrofit Increase Home Value?

If you live in an area that’s prone to seismic activity, an earthquake retrofit will definitely increase your home value. A home with earthquake protection is much safer, less expensive to insure, and tells potential buyers that they won’t need to pay for retrofitting themselves. All of these benefits mean earthquake retrofitting can have a drastic impact on your home’s value. It’s estimated that for every $1 spent on retrofitting, homeowners will save up to $7 to $13.

Budgeting for Earthquake Retrofitting

Earthquake retrofitting is an essential task in many areas, but it can come with a high price tag. Here’s a list of ways to save money on this important project:

• When possible, opt for less expensive materials, such as wood frames over more expensive metal ones.

• Make the investment in a skilled, experienced engineer to ensure quality work that will last you a long time.

• Look into tax write-offs and incentives—many cities and states offer rebates and other financial breaks for earthquake retrofitting.

• Opt for more inexpensive techniques, such as mudsill anchoring, as an alternative to more comprehensive and expensive measures.

• See if you can get together with neighbors who also want earthquake retrofitting for possible group discounts from a local foundation repair contractor.

How HomeAdvisor Gets Its Cost Data

No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. After a project is complete, we survey real customers about the costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.