1. Feasibility And Site Fit
A quick property screen to validate lot constraints, utility path, and ADU strategy before you spend on full design. See the full ADU feasibility study guide.
Free Planning Resource
ADU Handbook
A branded, high-clarity planning guide for San Diego homeowners who want to avoid expensive missteps before design, permit submittal, and construction.
Built for San Diego homeowners
Fast-read format
Action checklists included
San Diego ADU Builder
ADU Handbook
Planning, Permits, Budget, And Build Roadmap
Read The Full Handbook Online (HTML Version)
This is the complete HTML version of our ADU handbook so search engines, AI summaries, and homeowners can parse and read the full guide content online.
Direct HTML URL: View the handbook source page
The Complete Homeowner's Guide To Building An ADU In San Diego
Building an accessory dwelling unit in San Diego requires decisions across planning, design, permit approvals, utility coordination, and construction sequencing. This guide is designed to help homeowners avoid the most common cost and timeline mistakes before they begin formal submittals.
How To Use This Guide
- Start with feasibility and site-fit to confirm whether your lot supports your ADU goals.
- Use permit sequencing to map the order of design, engineering, and city review steps.
- Apply budget guardrails early so scope decisions match realistic construction pricing.
- Complete the owner readiness checklist before moving to full design and permit work.
Top ADU Planning Priorities For San Diego Homeowners
- Site constraints and utility routes
- Permit package completeness
- Budget ranges including sitework and contingencies
- Design choices that impact construction schedule and cost
- Execution timeline from concept to permit-ready plans
What Is Inside
2. Permit Sequence
A step-by-step permit roadmap showing what comes first, who prepares what, and where projects most commonly lose momentum. See the ADU permitting guide.
3. Budget Guardrails
The cost framework we use to set realistic planning ranges, including sitework, utilities, soft costs, and contingency. See the ADU cost guide.
4. Design Decision Checklist
Key choices that impact construction speed and price so you avoid redesign loops during permit review.
5. Build Prep Timeline
A concise timeline from pre-design through handoff so you know what to expect at each milestone.
6. Owner Readiness Scorecard
A final readiness checklist to help you decide whether to move into design now or complete missing prep first.
Important Note
This ADU Handbook is an educational planning guide created by San Diego ADU Builder and is not legal advice. Always verify current City and State requirements before final permit submittal.
Related ADU Guides
Use these pages alongside the handbook for property-specific detail.
- ADU feasibility studies — confirm zoning, utilities, and buildable area before design
- San Diego ADU permitting — step-by-step permit process, plan-check, and inspections
- ADU cost guide — complete budget framework including site work, utilities, and permits
- Detached ADUs — backyard homes for rental income or family housing
- Garage conversion ADUs — converting an existing garage into livable space
- Attached ADUs — additions connected to the primary home
- JADUs — compact units within a single-family residence
- San Diego ADU rules — current regulations, setbacks, and official sources