YOUR 2024 ADU COST GUIDE FOR SOUTHERN CALIFORNIA

Specification Information

ADU Feasibility, Design & Site Assessment: $1,000 to $2,500

We “front load” a lot of the work that is usually done later in the process. We want to assess the feasibility and all costs to build the ADU on your lot. The first step is to produce a site plan, map existing utilities, assess electrical panel loads, and create a feasibility report with your selected ADU plan mapped on your property. This will allow us to produce a guaranteed price for your project.

Construction Drawings: $8500 - 11,000+

Even with standard ADU plans, the ADU must be situated & adapted to your property specifics so that we can submit construction documents and application package with all required forms to the city. This comprehensive package includes all required architectural design, structural engineering, title 24, building code review with the city, permit processing, & any required revisions.

Permits and Fees $5,000+

While many ADU fees have been waived, there are still several due. We recommend estimating around $10-12/sq ft in ADU permit fees, though this varies by city and size. No impact fees apply for ADUs under 750 sq ft; for ADUs larger than 750 sq ft, impact fees are proportional to the size of the ADU in relation to the primary residence. School fees are also due, as well as sewer connection fees.

Basic Site Work: $25,000

For a level lot with sufficient access for construction equipment, typical sitework to prepare a buildable pad for the ADU will cost $25K. This includes trenching for the new utilities that will service the ADU. If you are rerouting utilities or building on a slope, additional costs can quickly escalate; read more below.

Additional Sitework: TBD

(OPTIONAL OR POSSIBLY REQUIRED) Additional ADU costs may come up based on your specific site. These are the biggest cost drivers we help you plan for. If you have a challenging property, you may also want to consider property reports (survey, title report, or a soil report) to properly plan for the ADU.

Vertical Building Construction: $150,000-400,000

The vertical building cost is for the ADU itself, including the foundation, structure, and standard finish materials.

Upgraded Finish Materials: TBD

Our basic finishes include electrical and plumbing fixtures, cabinets, and quartz countertops from our standard packages. You can also choose to upgrade any of these items per your choices.

Solar: $10,000-$20,000

All new construction detached ADUs are required to have solar, unless the main home already has solar installed, in which case that system may be expanded. Basic solar systems cost $15-20K to design & install depending on ADU size and energy use requirements (but you can claim a 30% federal tax credit on solar).