Garage Conversion Adu San Diego

Garage Conversion ADU in San Diego: The Complete Guide (2026)

Converting your garage into an ADU is the most affordable way to add a rental unit or extra living space to your San Diego property. With California's ADU-friendly laws and San Diego's high rental demand, garage conversions offer an excellent return on investment.

A garage conversion ADU in San Diego typically costs $80,000 to $150,000—significantly less than building a detached ADU—because you're working with an existing structure that already has a foundation and walls.

Garage Conversion ADU Costs in San Diego

Project Scope	Cost Range	Timeline
1-Car Garage (200-250 sq ft)	$60,000 - $100,000	8-12 weeks
2-Car Garage (400-450 sq ft)	$90,000 - $150,000	10-14 weeks
3-Car Garage (600+ sq ft)	$120,000 - $180,000	12-16 weeks

What's Included in a Garage Conversion

Required Work

• Insulation: Walls, ceiling, and floor to meet California Title 24 energy requirements
• Electrical upgrade: New panel or subpanel, outlets, lighting, dedicated circuits
• Plumbing: Kitchen sink, bathroom (toilet, shower, sink), water heater
• HVAC: Mini-split system or ducted heating/cooling
• Windows: Egress windows for bedrooms, natural light requirements
• Flooring: Raise and level the floor (garages slope for drainage)
• Drywall: Fire-rated drywall on shared walls with main house
• Kitchen: Cabinets, countertop, appliances, ventilation
• Bathroom: Full bath with shower required for ADUs

Optional Upgrades

• Separate entrance and address
• Private yard or patio space
• Washer/dryer hookups
• Upgraded finishes (quartz counters, tile floors)
• Smart home features

San Diego Garage Conversion Requirements

Building Code Requirements

• Ceiling height: Minimum 7'-6" (most garages meet this)
• Floor area: At least 150 sq ft (efficiency) or 220 sq ft (1-bedroom)
• Egress: Emergency escape window in sleeping areas
• Fire separation: 1-hour fire-rated wall if attached to main house
• Parking: Not required to replace lost garage parking

Permit Process

San Diego has streamlined ADU permits. The typical timeline:(See also: adu construction in La Mesa)

• Plan preparation: 2-4 weeks
• Plan check: 4-6 weeks (expedited options available)
• Permit issuance: 1-2 weeks
• Construction: 8-16 weeks
• Final inspection: 1-2 weeks

Rental Income Potential

San Diego garage conversion ADUs generate strong rental returns:(See also: adu construction in La Mesa)

• Studio (200-300 sq ft): $1,200 - $1,800/month
• 1-Bedroom (350-450 sq ft): $1,600 - $2,400/month
• 1-Bedroom+ (500+ sq ft): $2,000 - $2,800/month

At $1,800/month, a $100,000 garage conversion pays for itself in under 5 years while adding significant property value.

Garage Conversion vs. New ADU Construction

Factor	Garage Conversion	New Detached ADU
Cost	$80K - $150K	$150K - $350K
Timeline	3-4 months	6-12 months
Size Limit	Existing footprint	Up to 1,200 sq ft
Yard Impact	None	Uses yard space

Why Choose Cali Dream Construction

Cali Dream Construction has completed dozens of garage conversion ADUs throughout San Diego County. We handle everything from design and permits to construction and final inspection.(See also: adu construction in Vista)

Our garage conversion services include:

• Free feasibility assessment
• In-house design and engineering
• Complete permit processing
• Full construction management
• Fixed-price contracts with no surprises

Ready to turn your garage into rental income? Call (858) 434-7166 for a free consultation. Or try our Garage Conversion Calculator for an instant estimate.