ADU Cost Calculator

Get an instant estimate for your San Diego ADU project. Detached, attached, or garage conversion.

California ADU Specialist
2026 Prices
Instant Results

ADU Cost Estimate

Quick planning numbers for San Diego ADU projects - from garage conversions to fully detached units.

Based on recent projects in San Diego County with permits and a small contingency included.

ADU Types Explained

  • Detached ADU: Standalone unit separate from main home
  • Attached ADU: Addition connected to existing home
  • Garage Conversion: Converting existing garage to living space

California law allows ADUs up to 1,200 sq ft on most residential lots. Permits typically take 60-90 days in San Diego.

CA allows up to 1,200 sq ft

ADU Cost Ranges in San Diego (2026)

ADU costs vary significantly by type, finishes, and neighborhood. Here are typical ranges:

Garage Conversion

$120K - $180K

Attached ADU

$170K - $300K

Detached ADU

$200K - $400K+

What's Included in an ADU?

California ADU Benefits

ADUs are a smart investment for San Diego homeowners:

Ready to Build Your ADU?

Get matched with licensed San Diego ADU contractors. Free quotes, no obligation.

Get Free ADU Quotes

Homeowner Planning Tools

Get the Full ADU & Granny Flat Calculator Suite

Local San Diego planning guides · remodel calculators · free contractor estimate when you are ready

Open RemodelSD Calculator → All RemodelSD Calculators
Free Estimate — Call (858) 434-7166

ADU Construction Cost FAQ

How much does an ADU cost in San Diego?

ADU construction in San Diego costs $150,000-$400,000 depending on size and type. Garage conversions start around $80,000, while new detached ADUs average $200,000-$350,000.

How long does ADU construction take?

ADU construction typically takes 4-8 months including permits. Garage conversions take 3-4 months, new construction takes 6-10 months.

Do I need permits for an ADU in San Diego?

Yes, all ADUs require permits. San Diego has streamlined ADU permitting, but you still need building, electrical, and plumbing permits. Cali Dream Construction handles all permitting.

Can I rent out my ADU in San Diego?

Yes. California law allows ADUs to be rented. San Diego ADUs can generate $1,500-$2,500/month in rental income depending on size and location.

Our Network

Cali Dream Construction Escondido Home Remodeling Cali Dream Construction