ADU Structural Engineering Services

Get Permit-Ready ADU Structural & Civil Engineering Plans

Permits are usually handled by city building departments in incorporated cities, and by Los Angeles County for unincorporated areas. Garage conversion ADUs in this county often involve slab assessment, wall retrofit scope, and upgrades to support habitable use.

Licensed CA Engineers
Same-Day Quote
2-3 Weeks Delivery
Highly Responsive
Permit Guarantee(1)
Fixed Transparent Pricing
Licensed California Engineers|CA PE License #68517 - Amarendra Prasad, PE
3000+
Projects Completed
2-3 Weeks
Average Delivery
Guaranteed(1)
Permit Approval
4.8
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Serving projects across all of Los Angeles County

Los Angeles County has one of California's most active ADU markets, driven by housing demand, multigenerational use, and rental cost pressure. Projects include detached and attached ADUs, garage conversions, and infill additions across both dense urban neighborhoods and suburban tracts.

Why Build an ADU in Los Angeles?

  • Garage ADU Structural Design
    Structural evaluation and retrofit design for garage-to-ADU conversions. We assess the existing slab and framing, then engineer modifications for habitable use with full seismic compliance.
  • Permit-Ready Plan Sets
    PE-stamped plans built for fast approvals in Los Angeles County. The City of LA supports online plan submittals through the LADBS Express ADU permitting program.
  • Project Engineering Coordination
    Structural, civil, grading, and drainage engineering unified into one plan set for Los Angeles County ADU projects. We coordinate across consultants and handle permit responses — no gaps, no delays.

How ProStruct Helps

  • PE-stamped structural plans ready for permit submission
  • Foundation design, framing plans, and lateral system engineering
  • Structural calculations that meet California building code
  • Coordination with your architect and contractor
  • Unlimited plan-check revisions within engineering scope
  • Dedicated project manager — no extra cost
HOW IT WORKS

Fast, Easy & Convenient Process

1

Request a Free ADU Consultation

Share a few project details and our engineering team will review your scope and guide you through permitting and design next steps.

2

Get Same-Day Quote

After reviewing your project details, we'll provide a transparent quote the same day--typically within a few hours. Pricing varies based on project scope, complexity, and requirements.

3

Receive Permit-Ready Plans in 2-3 Weeks

We deliver complete structural permit sets. *If building departments have comments related to our scope, we handle all revisions--no extra fees, no limits.

SUCCESS STORIES

What Our Clients Are Saying

See why homeowners and industry professionals trust us with their projects.

Trusted by homeowners and AEC industry professionals

Fast delivery • Permit guarantee(1) • Fixed Transparent Pricing

COMMON QUESTIONS

Frequently Asked Questions

A garage adu involves garage conversion projects that transform existing garages into habitable units. California requires PE-stamped structural plans for every garage adu project.

Costs depend on project size, complexity, and site conditions. Our fixed-price quotes include:

• Structural calculations and PE-stamped plans
• Foundation and framing design
• Lateral system and seismic engineering
• Civil engineering coordination

Same-day quotes available — no hidden fees. Get a free quote for your Los Angeles County project.

Yes — California requires PE-stamped structural plans for every ADU. This covers foundation design, framing, and seismic compliance. This applies whether you're building in Los Angeles, Long Beach, Glendale, or unincorporated Los Angeles County.

Most Los Angeles County ADU plan sets are completed in 2–3 weeks — structural calculations, foundation design, framing plans, and civil coordination included. Rush service is available for urgent timelines.

We serve all cities in Los Angeles County including Los Angeles, Long Beach, Glendale, Pasadena, Torrance, Burbank, Santa Monica, West Hollywood, Culver City, El Segundo, Inglewood, and all unincorporated areas. Each city may have additional requirements, which we address in your plans.

Under California ADU law:

Detached ADUs: up to 1,200 sq ft
Attached ADUs: up to 850 sq ft
Junior ADUs: up to 500 sq ft

Specific limits may vary by city within Los Angeles County. We size and engineer your ADU to the maximum allowed on your lot.

Most ADUs don't require additional parking. Parking is typically waived when the ADU is:

• Within 0.5 miles of public transit
• In a historic district
• A conversion of an existing garage

Check with your specific city for local rules.

Yes — garage conversions are one of the most popular ADU types, and you typically don't need replacement parking. Our engineering scope covers slab analysis, wall framing, ceiling structure, and seismic design for Los Angeles County garage conversions.

The City of LA supports online plan submittals through the LADBS Express ADU permitting program. Other cities within LA County have their own processes, many transitioning to digital. We deliver PE-stamped plans in PDF, ready for submission — all required sheets, calculations, and documentation included. We also handle every plan-check comment through final approval.

Yes. Our construction admin services include:

• Contractor RFI responses
• Submittal review
• Structural site observations
• Certification letters

This ensures your ADU is built to plan and code.

Start your structural and civil engineering project

Ready to Start Your Project?

Get a free, no-obligation quote within 24 hours. Our experienced structural and civil engineers are ready to help with your residential or commercial project.

Free Quote in 24 Hours
2-3 Week Delivery
Permit Guarantee(1)
Call (844) 750-0773

Trusted by 3,000+ homeowners and AEC professionals • Licensed in California State • 35+ years experience

Garage Conversion ADU Structural Engineers in Los Angeles County, CA | ProStruct