ADU Design · Los Angeles County
Hundreds of ADUs Designed Across LA County. Yours Could Be Next.
Permit-ready ADU plans from one of the first firms in Los Angeles to specialize in Accessory Dwelling Units. Garage conversions, detached units, two-story ADUs — designed, engineered, and walked through plan check by the same team, start to finish.
- Designing ADUs since California’s 2017 legislation
- 1,500+ residential & commercial projects completed
- 10+ years in business — established, incorporated, insured
- Jurisdictions across LA County: City of LA, county, and beyond
- End-to-end: concept through permit issuance
7+
Years in Business
1100+
Projects Completed
2017
Designing ADUs Since
100%
Project Completion Rate
Recent ADU Work
ADUs We’ve Designed
Every style, every configuration — detached units, garage conversions, two-story designs. All drawn for real LA County lots and real LA County plan checkers.
Most ADU design packages are quoted as a flat fee after a free consultation — no hourly surprises.
Why Design 1 Studio
The ADU Firm That Was Here First
When California passed its ADU legislation, most firms were scrambling to figure out the rules. We were already drawing plans — and we’ve been at the forefront of every regulatory update since.
We Know the Rules Cold
Setbacks, height limits, parking exemptions, utility requirements — the details that trip up generalist designers are our daily work. We design to what your jurisdiction will actually approve, not what looks good on paper.
One Team, Start to Finish
Concept, construction documents, structural coordination, Title 24, permit submission, plan check corrections — handled by the same team. No handoffs, no disappearing designers, no project left half-done.
Built for LA County Lots
Small lots, hillside lots, odd setbacks, existing garages — we’ve designed ADUs for the lots other firms turn away. If there’s a compliant path to your unit, we’ll find it.
Our Process
Start to Finish
A four-phase process refined over ten years and 1,500+ projects — built to eliminate guesswork and keep your ADU on track.
I
Consultation
Free initial consultation. We evaluate your property, what your jurisdiction allows, and discuss feasibility, budget, and timeline.
II
Concept Design
Preliminary layouts, site plans, and design concepts developed in close collaboration with you. We refine until it’s exactly right.
III
Construction Documents
Complete, permit-ready plan sets including structural, mechanical, electrical, and plumbing coordination. Engineered and ready for submission.
IV
Permit & Beyond
We submit, we handle plan check corrections, and we support you through construction. We don’t disappear after the plans are drawn.
Common Questions
ADU Questions, Answered
Design fees depend on the size and complexity of the unit, whether it’s a conversion or new construction, and your jurisdiction’s requirements. After a free consultation, we quote a flat design fee in writing — so you know the full number before any work begins. Third-party costs like structural engineering and Title 24 calculations are itemized separately so there are no surprises.
Design and construction documents typically take 6–10 weeks depending on complexity and how quickly decisions are made. Jurisdiction review time varies by city — state law requires agencies to act on compliant ADU applications within set timeframes, but real-world review speed differs across LA County. During your consultation we’ll give you a realistic timeline for your specific city.
In most cases, yes — garage conversions are one of the most cost-effective paths to an ADU, and state law provides significant flexibility on setbacks and parking for conversions of existing structures. We’ll evaluate your garage’s structure, ceiling height, and utilities during the consultation and tell you honestly whether conversion or new construction is the better path for your lot.
Often, yes. Height limits depend on your jurisdiction and your lot’s zoning, but state law allows taller ADUs in many situations than most homeowners realize. We’ve designed numerous two-story units across LA County. If your lot qualifies, we’ll show you what’s possible during the consultation.
Yes — completely. We prepare the full submittal package, submit to your city’s planning and building departments, respond to plan check correction letters, and manage the project through permit issuance. You’re never left to navigate the counter on your own.
Site evaluation and feasibility, preliminary design concepts and floor plans, design review meetings with revisions, complete construction documents with structural coordination, Title 24 energy compliance, MEP plan coordination, site plan preparation, permit submission, and plan check correction responses. One package, one team, one accountable point of contact.
About the Studio
Built on a Decade
of Delivering
Design 1 Studio didn’t become one of LA County’s most trusted design firms by accident. For over ten years, we’ve been the team that owners, developers, and investors call when the project has to be done right — and done completely.
“We don’t start projects. We finish them. Every ADU we take on gets the full weight of our experience — from the first sketch to the day your permit is issued.”
Nathan Sewell · Design 1 Studio Inc.
Get Started
Let’s Design Your ADU
Whether you have a fully formed vision or just the seed of an idea, your first consultation is free. Tell us about your property and we’ll tell you what’s possible — honestly.