Earthquake Retrofits
Earthquake Retrofit & Structural Resilience
Earthquake retrofits strengthen the structural connection between a building and its foundation, helping reduce the risk of severe structural damage during seismic events.
WCCD (West Coast Construction & Development, CSLB #1135622) provides earthquake retrofit services focused on two common residential seismic improvements:
• Foundation bolting and cripple wall bracing (EBB)
• Soft-story strengthening for homes with living space above garages (ESS)
These structural upgrades are designed to improve building stability and align with retrofit approaches used in programs such as the California Residential Mitigation Program.
Our Services
Residential Seismic Retrofit Services
California earthquake mitigation programs focus on strengthening vulnerable building configurations and improving structural connections between a building and its foundation.
West Coast Construction & Development provides retrofit services aligned with commonly recognized seismic mitigation approaches, including the Earthquake Brace + Bolt program, soft-story structural strengthening, and dwelling retrofit verification inspections.
EBB RETROFIT
Retrofit Scope
• Seismic site review and vulnerability evaluation
• Foundation bolting with approved sill-plate anchors
• Cripple-wall bracing where present
• Water-heater bracing per EBB standards
Permits & Documentation
• Permits prepared to CEBC A3 and CEA EBB guidelines
• Before-and-after photo documentation upon request
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ESS RETROFIT
Structural Strengthening
• Soft-story evaluation of garage-level walls
• Engineered shear walls, blocking, and hold-downs
• Perimeter and garage-front anchorage
• Water-heater bracing per ESS standards
Permits & Documentation
• Permits prepared to CEBC A4 and CEA ESS guidelines
• Before-and-after photo documentation upon request
SERVICES
Information
INFORMATION
Understanding Earthquake Retrofits
During an earthquake, buildings are subjected to strong side-to-side forces caused by ground shaking. These forces place stress on the connections between the house framing and its foundation. A seismic retrofit strengthens these connections so earthquake forces can move more safely through the structure, improving how the building responds to seismic movement.
How Retrofits Strengthen a Home
Residential seismic retrofits focus on reinforcing key structural connections between the framing and the foundation.
Common improvements include:
-
Foundation anchoring
Small house cross-section showing the wood frame bolted to the concrete foundation. -
Cripple wall bracing
Small crawl-space diagram showing short wall framing with plywood sheathing. -
Soft-story strengthening
Small front elevation of a house with garage opening below and strengthened wall framing around it.
These improvements help reduce the likelihood of severe damage during earthquake ground shaking.
Common Seismic Retrofit Methods and Hardware
Earthquake retrofits use specialized structural connectors to strengthen the connection between a building’s framing and its foundation.
Framing Angle Connector (L90)
Steel connector used to reinforce framing connections.
URFP Foundation Plate
Retrofit connector used to strengthen sill plate anchorage to the foundation.
In a house without a cripple wall, the wall’s bottom plate (sill plate) sits directly on the concrete foundation and is typically anchored with foundation anchor bolts embedded in the concrete
Plywood shear panels: The large wood panels attached to the wall studs increase the wall's ability to resist side-to-side earthquake forces
Earthquake retrofit
WCCD delivers EBB and ESS retrofits and CEA Dwelling Retrofit Verification (DRV) inspections.
EBB Retrofit
Retrofit Scope
-
Seismic site review and vulnerability evaluation
-
Foundation bolting (approved sill-plate anchors)
-
Cripple-wall bracing where present
-
Water-heater bracing per EBB standards
Documentation
-
Compliance CEBC A3, and CEA EBB
-
Before-and-after photos for EBB submission
-
Contractor invoice with EBB cost breakdown
ESS RETROFIT
Structural Strengthening
-
Soft-story evaluation (garage-level walls)
-
Engineered shear walls, blocking, and hold-downs
-
Perimeter and garage-front anchorage
-
Water-heater bracing per ESS standards
Documentation
-
Compliance CEBC A4 and CEA ESS
-
Before-and-after photo documentation
-
Contractor invoice with ESS cost breakdown
Fire Hardening
Fire Hardening
WCCD delivers licensed Brace-and-Bolt and WCCD provides EBB and ESS retrofits and CEA Dwelling Retrofit Verification (DRV) inspections. All work follows CEBC Chapters A3/A4, FEMA P-1100, and CEA DRV requirements.
EBB Retrofit
Retrofit Scope
-
Seismic site review and vulnerability evaluation
-
Foundation bolting (approved sill-plate anchors)
-
Cripple-wall bracing where present
-
Water-heater bracing per EBB standards
Documentation
-
Compliance CEBC A3, and CEA EBB
-
Before-and-after photos for EBB submission
-
Contractor invoice with EBB cost breakdown
ESS Retrofit
Structural Strengthening
-
Soft-story evaluation (garage-level walls)
-
Engineered shear walls, blocking, and hold-downs
-
Perimeter and garage-front anchorage
-
Water-heater bracing per ESS standards
Documentation
-
Compliance CEBC A4 and CEA ESS
-
Before-and-after photo documentation
-
Contractor invoice with ESS cost breakdown
Earthquake retrofit
OUR PROCESS
Our Project Process: A Disciplined Path to Resilience
1
Initial Project Discussion
Projects begin with an initial project discussion and a limited preliminary review to understand the property, project objectives, and overall feasibility. Information provided by the client is reviewed to determine general alignment and identify potential next steps before any on-site visit is scheduled.
2
On-Site Visit & Scope Development
An on-site visit is conducted to observe structural configuration, site conditions, access constraints, and environmental exposure. Scope development is based on visible and reasonably accessible areas at the time of the visit and informed by IBHS principles, CEA retrofit guidance, and applicable California Building Code and WUI provisions. For fire rebuild or new construction projects, the visit may also include preliminary site evaluation and discussion of project objectives.
3
Implementation, Construction & Project Documentation
Construction and upgrades are executed with disciplined workmanship and professional oversight in accordance with the defined scope of work. Supporting project documentation may be provided upon request.