Get Your Southern California ADU or Garage Conversion Permit – Fast & Hassle-Free.
Permit-Ready Plans: We handle the technical heavy lifting so you can start building sooner.
Architectural | Structural | MEP | Title 24
1,000+ Residential Projects
California-Licensed Professional Engineers
Designed for City Approval
Serving OC & Southern California
Stop Paying Contractor Markups.
Work Directly with the Design Team.
Most contractors outsource their plans to firms like ours and add a 20-30% "management fee" on top.
By working directly with SBKN Engineering, you get factory-direct pricing on your engineering and architectural plans, saving you thousands before a single nail is driven.
What We Provide to Get You Approved
Full Architectural Design
Custom floor plans tailored to your property’s footprint. We maximize every square inch of your garage conversion or detached ADU.
Structural & MEP Engineering
Professional structural calculations combined with Mechanical, Electrical, and Plumbing (MEP) plans. We ensure your ADU is safe, efficient, and code-compliant.
Title 24 & Permit Management
Energy calculations (Title 24) included. We don't just hand you drawings; we provide a permit-ready package designed to sail through So-Cal city departments.
Why Homeowners & Contractors Trust SBKN Engineering
Licensed Expertise
With licensed Architects and Engineers on our team, every design we deliver meets the highest standards of safety, compliance, and precision. You can build with confidence knowing your plans are backed by credentials.
Code-Compliant & Permit-Ready
We know how to navigate California building codes, zoning rules, and permit requirements. Our drawings and plans are designed to get approved—fast—so your project doesn’t get stuck in red tape.
Reliable Timelines
Delays are costly. That’s why we commit to delivering plans and approvals on time, keeping your project moving forward without unnecessary setbacks.
Tailored Solutions
No two projects are alike. Whether it’s a simple garage conversion, a multi-unit ADU build, or a large commercial project, we customize our engineering services to match your goals, budget, and site conditions.
What Your Plans Will Include
The Complete ADU Permit Package
Site Plan & Floor Plans: Detailed architectural layouts.
Structural Calculations: Foundation, framing, and roof details.
MEP Layouts: Professional electrical, plumbing, and HVAC routing.
Title 24 Energy Reports: Essential for California compliance.
Direct Support: We answer city comments until your permit is issued.
What our clients say about us
“The structural plans were clear, thorough, and passed city review without issues. Exactly what we needed to keep the project moving.”
Emma W. | ADU
Orange, CA
“SBKN made the structural process simple. Fast turnaround, clear communication, and no surprises during plan check.”
Mark T. | ADU
Santa Monica, CA
“We’ve worked with several engineers—SBKN stands out. Their structural designs are practical and permit-ready.”
Sarah D. | Garage Conversion
Yorba Linda, CA
“From concept to approved structural plans, the experience was smooth and professional. Highly recommend their team.”
David S. | Single Family Home
San Bernardino, CA
“The structural calculations were clean and easy for our contractor to build from. Saved us time in the field.”
Oliver G. | Room Addition
Murrieta, CA
“SBKN understands how cities review plans. Their structural work helped us avoid revisions and delays.”
Sameer B. | Commercial
Roseville, CA
“Managing structural requirements used to be stressful. SBKN made the process straightforward and efficient.”
Lisa R. | ADU
Oakland, CA
“Great communication and solid engineering. SBKN was responsive and easy to work with from start to finish.”
Rachel P.
Ladera Ranch, CA
“Their team delivered exactly what was promised—clear scope, strong structural design, and fast turnaround.”
Tom F. | Commercial
San Marino, CA
Frequently Asked Questions
Are your plans ready for city submission?
Yes. Our deliverables are prepared specifically for permit approval.
Do you assist with plan check comments?
Yes, within the original project scope.
How long does it take to get an ADU permit in So-Cal?
Usually 2-4 months depending on the city’s backlog, but our design phase is much faster
Do you provide stamped calculations and drawings?
Yes. All structural drawings and calculations are prepared and stamped by licensed California Professional Engineers, when required.
Who do you work with?
Homeowners, contractors, commercial owners, property management companies and architects.
What areas do you serve?
Orange County and projects throughout California.
What’s the first step to get started?
Submit a Structural Project Review request through our form. We’ll review your information and reach out with next steps.
Can I convert my garage into an ADU?
Yes! Recent CA laws make garage conversions one of the fastest ways to add value.
Why should I hire an engineer before a contractor?
Having your own plans allows you to get "apples-to-apples" bids from multiple contractors and prevents them from overcharging for design.
Let’s Get Your ADU Project Approved
Fill out the form below for a free project consultation.
Find out exactly what you need to get your permit in Southern California.
