Planning your aDU in san diego
A step-by-step guide for homeowners - from feasibility to Certificate of Occupancy. Grounded in San Diego’s Municipal Code, DSD process, and current builder costs.
01
BEFORE ANYTHING ELSE
Know What You’re Building.
San Diego allows four primary ADU types. Understanding the difference shapes every decision that follows.
Detached ADU | Standalone structure. Max 1,200 sq ft. Most design flexibility, highest cost.
Attached ADU | Shares a wall with the main house. Often more cost-effective than detached.
Garage/Space Conversion | Converts an existing structure. Most affordable path.
Junior ADU (JADU) | Up to 500 sq ft inside your existing home. Owner-occupancy required.
Municipal Code: City of San Diego allows 1 ADU + 1 JADU per single-family lot. Bonus ADUs may be allowed if deed restricted ADUs are proposed.
02
FEASIBILITY FIRST
Check Your Lot Before You Design Anything.
This is the step most homeowners skip - and the one that causes the most delays later.
Zoning overlays: ADUs are allowed in all residential zones, but Coastal Overlay Zone, fire hazard, and hillside areas add review and constraints.
Easements: Easements may impact project viability and/or restrict development.
Lot size: No minimum lot size required by the city — but existing coverage matters.
Utilities: Separate electrical meters and sewer/water capacity are often required — check early.
Obtaining a site survey is helpful to understand the existing elements and boundaries of your property.
03
BUDGET REALITY
Know Your Numbers.
San Diego costs are among the highest in California. Current market ranges:
DETACHED ADU
$300k - $450k+
$375 - $600/sq ft. (new construction)
GARAGE CONVERSION
$80k - $200k
$200 - $400/sq ft. (reuses existing structure)
ATTACHED ADU
$160k - $280k
$300 - $450/sq ft. (shares a portion of the existing structure)
JADU
$30k - $80k
(interior work only)
Always budget a 15–20% contingency. ADUs under 750 sq ft are exempt from development impact fees (California SB 13).
04
DESIGN + PERMITTING
Hire Your architect before your contractor.
Your Architect produces the documents that make the project approvable, and coordinates everything the City needs to issue your permit.
Site analysis and zoning confirmation for your specific parcel.
Design development and construction documents
Coordination with engineers and consultants
Permit submittal and correspondence with the City
Your Architect will guide you through every step of the process - from design and permitting to construction administration, if desired.
05
THE DSD PERMIT PROCESS
What to expect from the city
A standard ADU application typically takes 3–4 months from first submittal to permit issuance.
Pre-screen (intake)
DSD confirms your submittal package is complete.
Plan check review cycle
Planning, structural, and engineering review simultaneously.
Corrections & resubmittal
Most projects require at least one round of comments.
Permit issued
Coastal Zone projects add 2–4 months.
2-4 weeks
3-6 weeks / cycle
Varies
3-4 months total
Check current wait times at sandiego.gov/development-services/permits/timeline — updated weekly by DSD.
06
CONSTRUCTION
Breaking Ground.
Construction typically takes 5–7 months for a standard detached ADU. Start to move-in: expect 10–14 months total.
01
Site preparation — grading, utility trenching, layout staking
Coastal zone properties or complex sites can extend construction to 8–12 months. Early material selections keep the schedule on track.
02
Foundation and framing
03
Mechanical, electrical, plumbing rough-in
04
Insulation, drywall, finishes
05
Final inspections and certificate of occupancy
Why san diego homeowners
are doing this.
THE LONG GAME
San Diego's tight rental market makes ADUs one of the most compelling financial moves a homeowner can make right now.
STUDIO / 1-BD (INLAND)
1-BR COASTAL / NEAR-COASTAL
$1,600-$2,400 / mo
$2,200-$3,000 / mo
2-BEDROOM
$2,500-$3,500 / mo
PROPERTY VALUE PREMIUM
approx. 35% higher vs. comparable homes
SEPARATE SALE (AB 1033)
Sell your ADU as a condo unit