How much does an earthquake retrofit cost?
How much does an earthquake retrofit cost?
$3,000 – $10,000 average retrofit cost
Average earthquake retrofit cost
Earthquake retrofitting costs $3,000 to $10,000, using techniques like anchoring and bracing to prevent quake damage. The cost to seismic retrofit varies based on a home's age, location, size, and foundation type. A structural engineer assesses these factors to determine seismic risks and recommend appropriate retrofitting methods for the property.
| Retrofit method | Average cost by method* |
|---|---|
| Anchoring to a mudsill | $1,000 – $2,500 |
| Cripple wall bracing | $1,000 – $3,000 |
| Foundation bolting | $1,000 – $5,000 |
| Shear wall reinforcement | $3,000 - $6,000 |
*Retrofits may include multiple methods.
Anchoring to a mudsill
Anchoring to a mudsill costs $1,000 to $2,500 and involves connecting the wooden sill plate (the horizontal beam resting on the foundation) to the concrete foundation using anchor bolts. This critical connection prevents the house from sliding off its foundation during seismic activity, providing essential structural stability.
Cripple wall bracing
Cripple wall bracing costs $1,000 to $3,000 and reinforces the short wood-framed walls between the foundation and first floor in crawl space homes. The process involves attaching structural grade plywood tightly to wall framing, creating a "shear wall" that prevents wall collapse during earthquakes.
Cripple wall bracing is especially crucial for homes built before 1980, as older construction techniques and building materials make these houses more vulnerable to seismic damage.
Foundation bolting
Foundation bolting ranges from $1,000 to $5,000 and connects the house's wooden structure directly to its concrete foundation. By installing bolts through the sill plate into the concrete, this technique prevents the building from separating from its foundation during ground movement, significantly reducing earthquake-related structural damage.
Shear wall reinforcement
Shear wall reinforcement costs $3,000 to $6,000 and strengthens walls to resist lateral forces during earthquakes. This involves adding structural elements like plywood sheathing, anchor bolts, and additional framing to create a more rigid wall system that can better withstand seismic movement and prevent structural failure.
Seismic retrofit cost by home size
The size of your home significantly impacts the overall cost of earthquake retrofitting. Homeowners can expect to pay between $3 and $5 per square foot for a seismic retrofit. Based on this pricing, the following table shows the estimated retrofitting cost for different home sizes.
| Home size (square feet) | Average cost range |
|---|---|
| 1,000 | $3,000 – $5,000 |
| 1,200 | $3,600 – $6,000 |
| 1,500 | $4,500 – $7,500 |
| 2,000 | $6,000 – $10,000 |
| 2,500 | $7,500 – $12,500 |
Earthquake retrofitting cost by home type
Different homes require various earthquake retrofits to strengthen their structure against seismic damage. The cost varies based on the home's design, construction, and unique vulnerabilities. For instance, hillside homes often need extra reinforcement, while soft-story buildings require structural modifications.
| Home type | Average retrofitting cost | Foundation description |
|---|---|---|
| Raised foundation | $5,000 – $10,000 | Elevated structure with crawl space |
| Soft-story | $15,000 – $25,000 | Weak first floor, often with parking |
| Post & pier | $5,000 – $10,000 | Elevated on individual posts or piers |
| Hillside | $7,000 – $20,000 | Built on sloped terrain |
| Mobile & manufactured | $2,000 – $10,000+ | Prefabricated, often on chassis |
Raised foundation
Raised foundation homes, which often have a crawl space under the first floor, are particularly vulnerable to earthquakes if built before 1980. Brace + Bolt retrofits, which cost $5,000 to $10,000, strengthen crawl space walls and secure the house to its foundation, helping to prevent sliding or toppling during earthquakes.
Soft-story
Soft-story homes, with living spaces above garages or large open ground floors, require additional support to enhance structural integrity and prevent collapse. Retrofits typically cost $15,000 to $25,000 and may include bracing garage walls, reinforcing the garage door area with plywood or steel, and adding new foundations or anchor bolts.
Post & pier
Post & pier homes rest on wood posts and concrete blocks without a continuous foundation, making them vulnerable during earthquakes. Retrofitting these homes usually costs $5,000 to $10,000 and involves adding a new concrete footing and plywood bracing to strengthen the foundation and prevent shifting or collapse in seismic events.
Hillside
Hillside home retrofits range from $7,000 to $20,000 due to their complex structural challenges. These homes often have weaker lateral support and are more vulnerable to earthquake damage.
Typical retrofits include adding foundation plates, anchors, and bracing systems to prevent swaying, with the retrofit complexity depending on the home’s design, slope steepness, and foundation condition.
Mobile home earthquake retrofit
Mobile and manufactured homes require stronger connections to the ground for better support against earthquake damage. Retrofitting a mobile home with an Earthquake Resistant Bracing System (ERBS) costs $2,000 to $10,000+ and significantly enhances stability by preventing sliding or collapse during seismic events.
Homeowners should consult a licensed structural engineer to develop a comprehensive retrofitting plan suitable for their location and home.
Cost to seismic retrofit a house by location
Earthquake retrofit costs vary significantly across different cities, primarily due to local seismic risks, building codes, and labor rates. The following table gives a breakdown of average retrofit costs in major earthquake-prone cities in California, the Pacific Northwest, and Alaska.
| City | Average cost |
|---|---|
| Los Angeles, CA | $3,500 – $6,600 |
| San Francisco, CA | $5,000 – $8,000 |
| Seattle, WA | $5,800 – $12,800 |
| Portland, OR | $2,800 – $6,300 |
| Anchorage, AK | $4,500 – $9,000 |
Earthquake retrofitting cost factors
Earthquake retrofitting costs depend on the home size, foundation type, retrofit methods, and local seismic risks. Larger homes require more materials and labor, different foundation types demand specific retrofit techniques, and homes in areas with higher seismic activity may require more extensive and expensive reinforcement measures.
Other factors that affect earthquake retrofitting costs include:
Insurance: Insurance policies typically do not cover retrofitting, but homeowners may qualify for lower insurance rates after completing the work.
Financing: PACE (Property Assessed Clean Energy) financing allows property owners to fund energy efficiency, renewable energy, and disaster resiliency improvements on their properties.
Foundation repairs: During the retrofitting process, existing foundation damage or vulnerabilities may be discovered, potentially requiring additional repair work. These additional foundation repair costs can impact overall project expenses.
After an earthquake, engineers use a color-coded tagging system, with green tags indicating the home is safe for occupancy. Proper retrofitting increases the chances of receiving a green tag, potentially saving you from costly repairs and relocation expenses.
Grants and loans
Homeowners in earthquake-prone regions can access various financial assistance programs to help offset retrofitting costs. Many states and local governments offer grants, loans, and financing options for seismic retrofits. These programs typically target homes built before current building codes, with assistance ranging from $3,000 to $13,000.
Funding sources may include federal agencies like FEMA, state emergency management offices, and local municipal programs. Check with your local housing authority, emergency management department, and state treasury office to explore available financial support for earthquake retrofitting.
Earthquake insurance
Earthquake insurance provides financial protection for homeowners, typically covering repairs to the house and attached structures, damaged belongings, and additional living expenses during home repairs. However, policies often come with high deductibles, sometimes 15% of the home's value, and may not fully cover extensive damage.
Beyond structural retrofitting, your earthquake preparation should include creating emergency plans that involve securing appliances, anchoring heavy furniture, and assembling an emergency supply kit.
Earthquake retrofit FAQs
What is earthquake retrofitting?
Earthquake retrofitting strengthens a house to help it survive earthquakes. It involves adding support to the foundation, walls, and connections to keep the house from falling apart when the ground shakes.
Is earthquake retrofitting worth it?
Retrofitting can save you money by preventing major damage during an earthquake. It makes your home safer, can lower insurance costs, and gives you peace of mind knowing your house is better protected. Seismic retrofitting is especially beneficial in older homes that are more vulnerable to earthquake damage.
How long does an earthquake retrofit take?
Most earthquake retrofitting jobs take 3 to 7 days to complete, depending on the scope of the work. In most cases, the work doesn't require entry to your home. Larger homes or those needing wall modifications will take longer. The total project timeline can extend from 4 to 12 weeks when considering planning, permits, and approvals.
What are the benefits of earthquake retrofitting?
Earthquake retrofitting provides critical protection for homeowners in seismically active regions, such as:
Enhances structural safety during seismic events
Reduces potential property damage
Lowers insurance costs
Increases property value
Minimizes legal and financial risks
Getting estimates for earthquake retrofitting
When hiring a foundation repair contractor for seismic retrofitting, consider these tips:
Verify experience: Look for contractors with extensive knowledge of seismic retrofitting, specifically in your type of building and local building codes.
Check licensing and insurance: Confirm the contractor is currently licensed, in good standing, and carries full-scale insurance coverage for retrofit projects.
Request detailed quotes: Seek comprehensive estimates that clearly outline the full project scope, potential challenges, and total costs.
Ask for references: Request and contact previous clients to verify the contractor's quality of work and customer satisfaction.
Evaluate expertise: Ensure the contractor understands current seismic retrofit guidelines, the local building codes, and has specialized knowledge of structural reinforcement techniques.
Prioritize quality over cost: Avoid choosing the cheapest option, as seismic retrofitting is a critical safety investment that requires skilled professional work.
Confirm in-house capabilities: Prefer contractors with their own skilled crews rather than those who rely extensively on subcontractors.
Understand their approach: Ask about their specific methods for addressing your building's unique structural needs and potential vulnerabilities.
Questions to ask your structural engineer or contractor
Ask the structural engineer or seismic retrofit contractor these important questions before you sign a contract:
What specific retrofit methods do you recommend for my property's structure?
Will the proposed retrofit meet current building code standards in my area?
How will these modifications improve my building's earthquake resistance?
What is the estimated total cost of the retrofitting project?
How long will the retrofitting process take to complete?
Will I need to obtain special permits?
What level of earthquake protection can I expect after the retrofit?
Do you provide a warranty for your work?
Can you provide references from similar retrofit projects?
Using our proprietary cost database, in-depth research, and collaboration with industry experts, we deliver accurate, up-to-date pricing and insights you can trust, every time.