California structural engineering for permit-ready projects.
Work directly with a California-licensed engineer for residential and commercial structural design, foundation inspections, calculations, and permit drawings. Start with a free project consultation.
Engineering rigor, made legible.
We translate architectural intent into a sound, code-compliant structural system — and a coordinated permit set with ongoing structural plan-check support.
- 01DiscoverReview drawings, site, and structural intent.
- 02AnalyzeRun gravity and lateral analysis against current code.
- 03EngineerDesign the structural system and detail the connections.
- 04Stamp & SubmitDeliver stamped calculations and plan-check support.
Structural engineering across the full project lifecycle.
Seismic Retrofit
Lateral analysis and retrofit design for existing California homes and buildings.
- —Soft-story evaluation
- —Foundation bolting
- —Shear wall design
Load-Bearing Wall Removal
Beam, post, connection, and footing design for safe open-concept remodels.
- —Beam sizing
- —Point-load analysis
- —Permit drawings
Foundation Engineering & Inspection
Foundation inspection, evaluation, repair design, and new foundation engineering.
- —Structural inspection
- —Settlement evaluation
- —Repair or new design
Structural Calculations & Permit Drawings
Signed structural calculations and coordinated drawings for building permit review.
- —Gravity and lateral calculations
- —Structural permit drawings
- —Plan-check responses
ADU Structural Design
California ADU structural engineering coordinated for permit and construction.
- —Foundation and framing design
- —Seismic load path
- —Permit coordination
SB 721 Balcony Inspection
Exterior elevated element inspections, reports, and repair design for California multifamily properties.
- —Exterior elevated element inspection
- —Signed inspection report
- —Repair recommendations
Clear engineering from first review through plan check.
Licensed engineer in responsible charge
Structural documents are reviewed and signed within the engineer's professional responsibility.
Permit-focused coordination
Calculations and details are coordinated with the architectural set before submittal.
Precise site conditions
Matterport 3D scanning captures the existing structure exactly, eliminating field surprises.
One coordinated team
One studio handling the structure end to end, working directly with your architect and crew.
Mason (Lei) Zheng
Founder & Principal Engineer, CMZStudio
California Professional Engineer
Licensed engineering from first calculation through plan check.
Lei Zheng has held a California Civil Engineer license since 2006. At CMZStudio, he reviews structural decisions, prepares and stamps engineering documents, and supports responses through city plan check.
Official California DCA record
C-69809
- License holder
- Lei Zheng
- License type
- Civil Engineer
- Issued
- March 17, 2006
Status verified July 23, 2026
- California-licensed
- 20 years
- Official DCA record
- C-69809
Featured projects.
Hillside Residence Retrofit
Seismic RetrofitFull seismic retrofit of a 1960s hillside home on a stepped foundation.
- Location
- Oakland, CA
- Status
- Complete
- Size
- 2,400 sq ft
Open-Concept Remodel
Load-Bearing Wall RemovalRemoved two load-bearing walls to create a single great room.
- Location
- San Jose, CA
- Status
- Complete
- Size
- 1,800 sq ft
Mixed-Use Foundation
Foundation EngineeringNew foundation system for a three-story mixed-use building.
- Location
- Fremont, CA
- Status
- In progress
- Size
- 12,000 sq ft
Detached ADU Structural Design
ADU Structural DesignStructural design for a detached backyard ADU on a tight urban lot.
- Location
- Albany, CA
- Status
- Complete
- Size
- 500 sq ft
SB721 Balcony Inspection
Balcony / SB721 InspectionExterior elevated element inspection and repair specification for a multifamily building.
- Location
- Bay Area, CA
- Status
- Complete
- Size
- Multifamily
Built for the people who get projects built.
- Homeowners
- Retrofits, additions, and open-concept remodels, engineered and permit-ready.
- Architects
- A structural partner who matches your set and protects the design intent.
- General contractors
- Buildable drawings with the connections detailed for the field.
- Developers
- Foundation and lateral systems for residential and mixed-use builds.
Thumbtack reviewsHundreds of reviews. A top-ranked Thumbtack Pro.
Read client feedback and review our public service history before choosing your engineer.
View Thumbtack profile- Hundreds of client reviews
- Top-ranked local Pro
- Public profile
“The calculations were clear enough that plan-check approved on the first submittal. No back-and-forth, no delays.”
“They walked us through the retrofit options in plain language and stood behind the numbers. The whole job felt handled.”
“We removed two bearing walls for an open kitchen. The beam sizing was exact and the framing crew had everything they needed.”
Structural engineering across California.
Based in Concord and serving the San Francisco Bay Area and beyond, with stamped structural work for residential and commercial projects statewide.
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