Design & Permitting

Easy as 1,2,3

OneStop ADU, the backyard home experts, will get you started on your companion unit project as easy as 1,2,3.

Free In-person Consultation

Pre-designed Architectural Plans

Permit Processing

Free in-person consultation

If you own a single-family home or multi-family property in the state of California, you are most likely eligible to build a backyard home.  In advance of your initial consultation, we will conduct a basic feasibility study of your San Diego property to verify all local and state rules. We will also verify allowable sizes and suggest general placement of your new structure. Next, our OneStop ADU team will meet with you to gain an understanding of your vision for your casita.  This initial no-cost meeting and feasibility study will help you decide if building a backyard home is right for you.

Pre-designed Architectural Plans

California’s current law allows you to build a 1200 sq ft maximum detached casita with a height limit of 16′ without any local discretionary approvals. Certain local municipalities have their own ADU ordinances. However, the state requires them to approve granny flats less than 850 sq ft, or up to 1,000 sq ft for a backyard home that contains one or more bedrooms.

OneStop ADU’s pre-designed plans and pricing will make it as easy as 1,2,3 and help keep uncertainty out of the picture. Once site analysis is complete, you can select your companion unit based on our findings. Since plans are already created, we save you money, time and the hassle of the lengthy back and forth design process and your permit application can be submitted to the city more quickly. Depending on the plan and finishes selected, your total cost including design, permitting and construction fees start at approximately $260/sq. ft*. Our in-house licensed building team has over 25 years of experience constructing homes and multi-family buildings in the San Diego area. We are a licensed contractor and do not sell prefab units like many of our competitors. We offer three exterior styles- Contemporary, Craftsman and Spanish/Mediterranean. OneStop ADU's construction pricing includes architectural and structural plans, Title 24 report, permit processing, individually metered electrical upgrade (does not include SDG&E fees) and required solar for your ADU based on requirements for Climate Zone 7. OneStop ADU makes it easy for you, offering six floor plans/sizes with interior and exterior visuals and a choice of interior finish packages.

We are your OneStop shop to make your backyard dream home a reality from inception to finished product!

* Based on current pricing July 1, 2022. Due to volatility in material and labor costs and supply chain issues, pricing may change.


The permitting process can be daunting, the team at OneStop ADU takes care of the entire process from A to Z on your behalf. Building permits and inspections are required by law for all new construction to ensure that the structure is built according to code.

Our pre-designed plans and construction drawings have been “design engineered” with essential elements in mind. Space optimization, natural light, energy consciousness and efficient construction have all been considered. Since our plans are pre-designed, the timeline from inception to creation of your dream backyard home will be shorter. Following our intake meeting, we will evaluate zoning, building codes and any applicable health and safety codes. After you select your companion unit model, we present plans, process all permits and work with the city that presides over the jurisdiction of your primary dwelling. The team at OneStop ADU will coordinate the inspection timeline to ensure a streamlined process.

We Want to Hear From You

Contact OneStop ADU today. We serve owners and investors in the entire county, including San Diego, Chula Vista, Oceanside, Carlsbad, and the surrounding areas.

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