Custom ADU Builder San Diego
Compare custom scope, site constraints, model options, finish level, construction sequence, and written pricing before selecting a build approach.
San Diego County · California
San Diego ADU design & construction
San Diego distinguishes ordinary ADUs from its ADU Home Density Bonus Program. The bonus route carries additional affordability, location and fee conditions that should be reviewed before using a multi-unit concept.
Full-service ADU construction
Custom ADU builder & contractor services in San Diego
Start with a custom ADU builder or ADU contractor in San Diego, then coordinate design, architecture, engineering, permits, budgeting, construction, inspections, and handoff around the property.
ADU Contractor San Diego
Coordinate construction scope, subcontractors, schedule, inspections, site logistics, and closeout around a clearly defined permitted set.
ADU Design Build San Diego
A coordinated design-build workflow keeps property review, design, engineering, permitting, budgeting, procurement, and construction aligned.
ADU Design San Diego
Develop the floor plan, exterior direction, material selections, functionality, and site fit before committing to engineering and construction.
ADU Architect San Diego
Architectural planning can address layout, massing, code constraints, site relationships, and permit drawings where an appropriately licensed professional is required.
ADU Engineer San Diego
Engineering coordination can cover structural, foundation, utility, civil, energy, and other disciplines required by the property and permitting authority.
Local planning guide · Reviewed October 2, 2026
What matters for an ADU in San Diego
Permitting authority: City of San Diego — Information Bulletin 400
Official local guidanceLocal rules and design checks
| Topic | Local guidance |
|---|---|
| Bonus-program rules | Check the current density-bonus eligibility, affordability restrictions and applicable fire or evacuation requirements. |
| Condominium path | Bulletin 400 describes a conditional subdivision process; separate sale is not automatic with an ADU building permit. |
| Plan licensing | The City directs owners to obtain permission and pricing from the provider of a preapproved plan. |
Selected local requirements, not a complete zoning determination. Confirm the current rules for your address with the responsible agency.
Fees and budget checks
Budget using Bulletin 501 plus the ADU-specific categories in Bulletin 400. San Diego identifies General Plan Maintenance fees, school fees where applicable and additional fee categories for multi-ADU or bonus-program projects.
San Diego construction permit fee scheduleHow to start the permit process
Use the Development Services portal’s Building Construction application for a new permit. Identify whether the proposal uses ordinary ADU rules or the bonus program before submitting.
Municipal application example
San Diego accepts specified regional plan resources
The City’s new-housing instructions identify County of San Diego and Encinitas PRADU plans as accepted resources, subject to the City application and review.
View the original sourceSan Diego ADU questions
- Is a bonus ADU assessed exactly like an ordinary ADU?
- No. San Diego lists program-specific affordability and Community Enhancement Fee conditions.
- Can I sell a new ADU immediately as a separate home?
- A separate condominium subdivision process and its conditions must be satisfied; the building permit alone does not accomplish that.
Sources for this guide
- City of San Diego — Information Bulletin 400
- San Diego construction permit fee schedule
- San Diego accepts specified regional plan resources
- San Diego regulatory updates
Local sources reviewed October 2, 2026. Historical examples retain their stated dates. Contact ADU California Inc. to confirm project availability; this guide does not establish an office location or property approval.
A useful first review
Separate what is available from what still needs verification.
01
Confirm the property
Start with a complete address and review the available parcel, building, and map context.
02
Identify the unknowns
Keep missing setbacks, easements, utilities, access, hazards, and local requirements visible.
03
Choose the next review
Use the preliminary result to prepare a focused conversation with the required professionals and agencies.
Explore project types
Compare the scope before choosing a solution.
These pages explain the questions each project type introduces. They do not assert that a particular scope is permitted or suitable for your address.
Compare planning footprints
See common ADU sizes before choosing a design.
These model pages are planning references only. They are not a statement that a particular size is allowed or buildable at a San Diego address.
California directory
Explore more city guides.
The next useful action
Put your address at the center of the conversation.
The online review is preliminary and is not a permit decision, survey, engineering opinion, construction document, final price, or guaranteed schedule.