8880 Rio San Diego Drive 8th Floor, CA 92108

ADU Design

We turn your dreams into reality x

S3DA is a design company that specializes in full-service, accessory dwelling unit projects throughout California.
We are facing affordable concerns, additional room for loved ones, and intelligent investors looking for ways to create a great rental property investment without buying an entire house. We have experience in Garage Conversion, Storage Conversion, Loft Conversion, Barn Conversion, JADUs, detached and attached additions

ADU Design

Our Firms’ expertise in ADU design core is


  • Conceptual Design
  • Structural Design
  • MEP Design
  • Title 24

Need help with your architectural design?

Evan Wyatt Bliss

Owner & Design Director at STUDIO BLISS LLC

“S3DA Design is one of the best structural and MEP design companies we’ve worked with. Their entire team always delivers us projects of exceptional quality while staying on schedule and under budget. They offer full package design services as well and virtually handle any design projects. We have chosen to work with S3DA Design on our projects”

ADU Design

Chris Cox

Chief Consultant, Development & Planning at BeGreenLegal Cannabis Consulting

“S3DA contacted me through LinkedIn and while I am usually skeptical of cold messages, I was in need of an MEP engineer so I thought I would give them a shot. After more than a year of working on several projects with their team, I have found them to be responsive, reasonable with timelines and budgets, and willing to stand behind their work. While there are many good engineers out there, S3DA’s customer service stands out as a valuable resource.”

ADU Design

Joe Serrano

CEO/Exec. Director at TentMakers Inc./ReCycled Housing

S3DA Design is a very critical engineering partner for us and our clients because of their attention to detail and professional relationship building skills. They have a very sincere concern for the quality of their work and satisfaction of their clients. Our company provides residential design services requiring the services of a professional structural engineering firm. We have worked with other engineering firms in the past, but S3DA Design has out performed all competitors on several fronts including pricing. But more importantly, it is S3DA’s relationship building and communication skills that have impressed me the most. They sincerely care about the quality of their work and the satisfaction of their clients. I highly recommend them and their work.

Joe Serrano

Brenda Hurley

Licensed Realtor at Excel Realty

S3DA is a very conscientious engineering firm with the mindset of coming up with the best solutions for its clients that are effective and cost-efficient. I would recommend S3DA to support your structural designs on your project.

Brenda Hurley

Belal Siddiqui

Owner of Mobius Designs 

S3DA Design team are a good hard working group of professionals. They provide great communication, drawings and feedback during all aspects of the design and permitting process. I have worked with them on multiple commercial and residential projects and they always deliver in a timely manner and are priced very well. I recommend using them on any project. Their drawings are methodical and easy to understand, which makes the job easier for everyone!

Belal Siddiqui

Steve Poehlein

Chief Designer at sp design+build

I truly enjoy working with the S3DA Design team. We have completed several projects and they are professional, communicative, and expedient. They deliver good solutions quickly for a competitive price.  Their work usually passes plan check on the first submittal. I highly recommend the S3DA Design team.

Steve Poehlein

New Testimonial

Principle at Locale Real Estate

S3DA Design did a great job for my team and me on structural engineering analysis. They were very responsive and easy to work with. The work product he provided was excellent and thorough, and the project plans we submitted passed a tough Building Department review. I would highly recommend S3DA Design.

ADU Design

Frequently Asked Questions

It depends on the complexity of the house, but in most cases, you will need roughly 5 to 8 sets. Those who will need design prints include:

  • The owner
  • The Contractor
  • The Sub-contractors
  • The Building Department
  • The Mortgage Lender
  • The Building Inspector

Yes, you can. If you or your builder have a talent for design, a clear idea of what you want, and if you can create plans that meet your local building authorities, you can go ahead with designing your house.

Well, it depends on several factors such as the complexity of the project, the square area of the land, add-on services like extra revisions, project management services or any type of construction help. We recommend you get in touch with our experts for a better understanding.

Different architects offer numerous services when it comes to initial meetings with potential clients. Many architectural design firms agree to a quick, one-off introduction free of charge to discuss the project, your budget and their ability to deliver.

Our architectural design firm offers

  • Conceptual Design
  • Exterior Design
  • Landscape Design
  • Design Development
  • Detailed Design and Drawings Production
  • Technical Specifications