Bernal Builders — ADU Builder & Garage Conversion Contractor in San Diego
Build an income-producing ADU or convert your garage with San Diego County's trusted contractor.
Full-service architecture, permitting, and construction for accessory dwelling units (ADUs) and garage conversions across San Diego County.
Bernal Builders, Inc., 3343 Durant Street, San Diego, CA 92113
San Diego Contractor | Licensed & Insured | Free Project Consult | Serving San Diego County
OUR EXPERTISE
Our ADU Services
From initial zoning approvals to the final coat of paint, we manage every phase of your accessory dwelling unit project. Explore our specialized services designed to maximize your property's potential.
Detached ADUs
Build a standalone backyard home perfect for rental income, extended family, or a private home office. We handle all zoning requirements and custom architectural designs to perfectly match your primary residence.
Junior ADUs
Convert an existing bedroom or underutilized space within your home into a fully functional Junior ADU (JADU). This highly cost-effective solution provides independent living spaces while bypassing standard permitting hurdles.
Transform your unused or underutilized garage into a beautiful, income-producing living space. Our conversion process optimizes existing structures to save on foundation and framing costs while delivering a premium finish.
ADU Additions
Expand your home's footprint with an attached ADU. Ideal for seamless generational living, attached units blend perfectly with your existing architecture while providing a distinct, private living area with its own entrance.
Design & Permitting
Navigate the complexities of local zoning laws and building codes with our expert pre-construction team. We provide complete architectural blueprints and secure all necessary city permits to ensure a stress-free start.
Contractor & Build
Experience a streamlined construction phase with our dedicated in-house builders. We manage the entire build process—from pouring the foundation to installing premium finishes—ensuring on-time delivery and uncompromising quality.
Complete ADU & Garage Conversion Services
Bernal Builders, Inc. provides complete ADU and garage conversion solutions from concept to completion, tailored for San Diego homeowners who want to add comfortable, code-compliant living space.
The team can assist with planning, design coordination, permits, engineering coordination, construction, and final inspections so you have guided support at every step.
Detached ADUs
Add a standalone backyard home for family or rental income. Bernal Builders guides you through planning, permits, and construction to create a comfortable, private unit.
Attached ADUs
Extend your existing home with an attached ADU that blends with your current layout. The team coordinates design, engineering, and permitting to keep the project moving smoothly.
Garage Conversions
Transform an underused garage into a livable ADU, guest suite, or office. Bernal Builders manages structural upgrades, permits, and inspections to meet San Diego codes.
Junior ADUs (JADUs)
Create a compact Junior ADU within your existing home for flexible living or rental space. The team helps refine layouts, coordinate design, and prepare plans for approval.
Room Additions
Expand your living room, bedroom, or create a new suite while maintaining the look of your existing home. Bernal Builders coordinates structural design and construction details.
Guest Houses
Design a welcoming guest house for visitors or multi-generational living. The team helps with layout, comfort features, and coordinating permits and inspections.
Home Offices
Create a quiet, dedicated home office or studio separate from daily household activity. Bernal Builders plans layouts, electrical needs, and finishes that support focused work.
Rental Unit Conversions
Convert existing space into a safe, rentable unit that aligns with local requirements. The team supports planning, coordination with engineers, and construction to meet your goals.
SAN DIEGO'S TRUSTED ADU EXPERTS
Why Choose Bernal Builders
Licensed, Insured & Fully Bonded
- State Licensed Contractor: Valid California License #C-XXXXXX
- Comprehensive Protection: Fully bonded with $2M+ in liability insurance
- Vetted & Approved: A+ Better Business Bureau rating
Fully
Insured
State
Licensed
A+ BBB
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San Diego Expertise & Code Compliance
- Local Zoning Masters: Navigating San Diego's specific ADU setbacks and regulations seamlessly
- Utility Connection Experts: Avoiding costly mistakes with specialized knowledge of local grids
- Project Warranty: 10-year comprehensive structural warranty on all builds
SAN DIEGO ADU OPTIONS
Which ADU is right for me?
Understanding your options is the first step. Explore the four primary ADU types available in San Diego, including average costs, timelines, and the best use cases for each to help you make an informed decision for your property.
Detached ADU
A completely standalone unit built in your backyard, offering maximum privacy for tenants or family members.
- Size: 400 - 1,200 sq ft
- Est. Cost:
- Timeline: 6 - 12 months
- Ideal for: Rental income, complete privacy
Attached ADU
An addition that shares at least one wall with your primary residence, expanding your home's footprint efficiently.
- Size: 300 - 1,000 sq ft
- Est. Cost: $100k - $250k
- Timeline: 5 - 9 months
- Ideal for: Aging parents, limited yard space
Junior ADU (JADU)
Created entirely within the existing walls of your single-family home. A cost-effective way to add an independent suite.
- Size: Max 500 sq ft
- Est. Cost: $50k - $100k
- Timeline: 3 - 6 months
- Ideal for: Budget-friendly, strict zoning
Conversion ADU
Transforming an existing garage, basement, or barn into a livable space. Maximizes your current property structures.
- Size: Varies by structure
- Est. Cost: $80k - $150k
- Timeline: 4 - 8 months
- Ideal for: Repurposing unused space
TRANSFORM YOUR SPACE
Garage-to-ADU Conversions (San Diego)
Turn your underutilized garage into a high-value rental unit, guest suite, or primary living space with our specialized conversion process.
What the Process Entails
- Structural Changes: We handle foundation and slab evaluations, advanced framing, proper insulation, and fire-rated separation walls required for attached garages. Seismic tie-downs and roof modifications ensure a safe, long-lasting dwelling.
- Complete Utility Upgrades: Upgrading an older garage means installing new electrical subpanels with dedicated circuits, comprehensive plumbing rough-ins, proper sewer connections, and energy-efficient HVAC mini-split systems tailored to Title 24 standards.
- Accessibility & Usability: Planning for the future with zero-step entry options, widened door clearances, optimized bathroom layouts, and slip-resistant surfaces for multi-generational living.
- Navigating San Diego Permits: We manage the specific local hurdles—from dealing with setbacks and nonconforming structures to replacement parking requirements and Title 24 energy compliance.
BEFORE: Standard 2-Car Garage
AFTER: Modern 1-Bed ADU
FEATURED CASE STUDY
North Park Garage Transformation
We transformed an underutilized 400 sq. ft. detached garage into a modern rental unit, handling comprehensive framing, new utility trenching, and securing all Title 24 compliance permits.
Timeline: 4.5 Months
Cost: $115,000
Outcome: $2,200/mo rental income
OUR PROCESS
Our 8-Step ADU & Garage Conversion Process
From your first phone call to the day you receive your certificate of occupancy, we manage every detail. Here is exactly what to expect.
STEP 1
Consultation & Site Survey
Timeline: 1-2 Weeks
Homeowner Prep: Gather property records, survey, and your wish list.
STEP 2
Design & Estimate
Timeline: 2-4 Weeks
Homeowner Prep: Review design drafts and approve final layout.
STEP 3
Permit Filings
Timeline: 4-12 Weeks (City Dependent)
Homeowner Prep: Sign required forms; we handle the city interactions.
STEP 4
Foundation & Mechanical
Timeline: 2-3 Weeks
Homeowner Prep: Clear access to the build site and ensure gates are unlocked.
STEP 5
Framing & Rough-Ins
Timeline: 3-4 Weeks
Homeowner Prep: Prepare for moderate construction noise during working hours.
STEP 6
Inspections
Timeline: 1-2 Weeks
Homeowner Prep: No action needed; we coordinate all city inspectors.
STEP 7
Finishes
Timeline: 3-5 Weeks
Homeowner Prep: Finalize fixture, paint, and flooring selections with our team.
STEP 8
Close-Out & Onboarding
Timeline: 1 Week
Homeowner Prep: Final walk-through and receive your keys and occupancy certificate.
SAN DIEGO ADU COMPLIANCE
Permits & Zoning (San Diego County ADUs)
Navigating local regulations is the most critical phase of your project. We handle the entire permitting pathway for San Diego County and City jurisdictions, ensuring your build complies with all zoning laws, setbacks, and local ordinances.
- Zoning & Setbacks: Standard 4-foot side and rear setbacks apply to most detached ADUs. We maximize allowable Floor Area Ratio (FAR).
- Parking Exemptions: Off-street parking is typically waived if you are within a half-mile of public transit or converting an existing garage.
- Overlays & Special Districts: Properties in the Coastal Zone or Historic Districts require specialized reviews. We manage all Coastal Development Permit requirements.
- Utilities & Impact Fees: ADUs under 750 sq. ft. are exempt from standard impact fees. We determine if shared or separate metering is best for your lot.
- Title 24 Energy Compliance: New detached ADUs must meet California's strict energy codes, including mandatory solar panel installations.
Actionable Steps & Timeline
1. Feasibility Check: Assess lot size, easements, and utility access (1-2 weeks).
2. Design & Engineering: Draft architectural and structural plans (4-6 weeks).
3. City/County Submission: File for plan check and address redlines (2-4 months).
4. Permit Issuance: Final approval to break ground.
Official Resources:
City of San Diego ADU Page | County Planning & Development Services
Permitting FAQs
How long does the permit process take in San Diego?
Typically, the plan check and approval process takes between 3 to 6 months, depending on current city/county backlogs and whether your property is in a special overlay zone.
Do I have to install solar panels?
Yes, for new detached ADU construction, California Title 24 energy code mandates solar panels. Conversions or attached ADUs generally do not require new solar arrays.
Can I rent my ADU on Airbnb?
San Diego regulations generally prohibit short-term rentals (less than 30 days) for newly permitted ADUs. They are intended for long-term housing.
Ready to build?
Get a comprehensive permit and zoning review tailored specifically to your lot.
No credit card required.
Understanding ADU Regulations in San Diego County
Accessory dwelling unit (ADU) regulations in San Diego County can vary based on your city or jurisdiction, property characteristics, zoning designation, and the type of ADU you plan to build. Local and state rules are updated over time, so homeowners should always verify current requirements with the appropriate planning and building departments before moving forward.
The information in this section is for general educational purposes only, is not legal advice, and does not guarantee permit approval or any specific result. Homeowners should consult qualified professionals and local agencies for guidance on their particular situation.
Detached ADUs
Detached ADUs are stand-alone homes on the same lot as the main residence. Within San Diego County, cities often set their own limits on maximum size, height, setbacks from property lines, and parking, so requirements can differ from one community to another.
Attached ADUs
Attached ADUs share at least one wall with the primary home. Local regulations may cap the ADU’s total square footage compared to the main house and control where additions can be placed on the lot, such as in the rear or side yard only.
Junior ADUs (JADUs)
Junior ADUs are smaller units created entirely within the existing footprint of a home. In San Diego County they are typically subject to strict size limits and specific rules for entrances, kitchenettes, and owner-occupancy on the property.
Garage Conversions
Converting a garage to an ADU generally requires bringing the structure up to current building, fire, and energy standards. Parking rules and whether replacement parking is required can depend on your specific location, transit access, and the policies of your city or the County of San Diego.
Zoning Requirements
Zoning rules help determine whether an ADU is allowed on a particular lot, what minimum lot standards apply, and how many units may be built. Standards can differ between incorporated cities and unincorporated areas of San Diego County, so it is important to check your exact jurisdiction.
Building Permits
Most ADU projects in San Diego County require one or more building permits and plan reviews. These reviews are intended to confirm that structural, safety, and accessibility standards are met before work begins and as construction progresses.
Utility Connections
ADUs need safe, code-compliant connections for water, sewer, electricity, and sometimes gas. Local agencies and utility providers in San Diego County may have their own standards, application processes, and connection or capacity fees for new units.
Final Inspections
At the end of construction, final inspections are usually required before an ADU can be legally occupied. Inspectors review the completed work to confirm it generally matches the approved plans and appears to comply with applicable codes and conditions of approval.
Bernal Builders helps San Diego County homeowners understand the ADU process and coordinates with designers, engineers, and other professionals as needed through planning, permitting, and construction. Bernal Builders cannot provide legal advice or guarantee that any permit will be approved; homeowners are responsible for confirming all requirements with the appropriate agencies.
INVESTMENT & RETURNS
Transparent Costs & Financing Options
We believe in no-surprise pricing. While every lot is unique, here is a clear look at typical investment ranges and how our clients fund their builds.
Estimated Investment Ranges
These non-binding estimates cover design, permitting, and standard construction:
- Garage Conversions: $90,000 - $120,000+
- Attached ADUs: $120,000 - $180,000+
- Detached ADUs: $150,000 - $250,000+
Key Cost Drivers
Final pricing depends on site preparation needs, utility trenching distances, foundation requirements, and your chosen level of interior finishes.
Common Financing Paths
We can connect you with trusted lending partners who specialize in ADU funding:
- HELOC: Home Equity Line of Credit
- Construction Loans: Based on future home value
- VA & USDA Notes: Renovation-specific funding
- Grant Programs: Local ADU incentives
ROI & Value Scenarios
An ADU is a high-yield asset. Homeowners typically see an immediate property value increase of $100k - $200k, while generating $1,500 - $3,000+ in monthly rental income, often offsetting financing costs entirely.
Use our dynamic calculator or speak with an expert to get a tailored estimate for your lot.
LOCAL COVERAGE
Service Area Across San Diego County
Bernal Builders proudly serves homeowners across the entirety of San Diego County, delivering premium construction and remodeling services right to your doorstep. From the coastal communities of La Jolla, Del Mar, and Carlsbad to the inland neighborhoods of Poway, Escondido, and San Marcos, our dedicated team is strategically positioned to manage projects throughout the region. We understand that geographical logistics play a crucial role in project timelines, which is why we optimize our scheduling to ensure prompt, reliable on-site consultations and daily project management regardless of your specific location within the county. Our initial consultations include a comprehensive site evaluation, allowing us to assess your property's unique zoning requirements and topographical considerations firsthand. Whether you reside in the urban heart of Downtown San Diego or the sprawling suburbs of East County, our mobile crews are equipped to bring our signature craftsmanship directly to you, minimizing travel delays and maximizing productive building time.
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OUR RECENT WORK
Portfolio Gallery
Browse our recent ADU and garage conversion projects across San Diego County.
Note: Click on any thumbnail below to view full project details and floor plans.
Standalone ADU
North Park • 2025
Outcome: Renting for $2,400/mo
Garage Conversion
Ocean Beach • 2024
Outcome: Added 450 sq ft of living space
Attached ADU
Clairemont • 2025
Outcome: Multi-generational family suite
Garage Conversion
La Mesa • 2023
Outcome: Home office & guest studio
2-Story ADU
South Park • 2024
Outcome: $3,100/mo passive income
Backyard Casita
Encinitas • 2025
Outcome: Property value increased by 20%
Client Success
Trusted by Local Clients
4.8/5 Average Rating
Based on 150+ verified reviews
Bernal Builders transformed our outdated kitchen into a modern masterpiece. Their attention to detail and communication throughout the project was outstanding. We couldn't be happier with the results.
From the initial consultation to the final walkthrough, the team was professional and respectful of our time. They finished the ADU build ahead of schedule and exactly on budget.
We hired them for a complete garage conversion in our Westside neighborhood. The craftsmanship is top-notch, and the new space blends seamlessly with the rest of the house.
Finding a reliable contractor is tough, but Bernal Builders exceeded all our expectations. They kept the worksite clean every single day and delivered a stunning home addition.
YOUR ADU QUESTIONS, ANSWERED
Frequently Asked Questions
How much does it cost to build an ADU?
ADU costs vary widely based on size, location, and finishes, typically ranging from $150,000 for a simple garage conversion to $350,000+ for a detached custom build. This includes design, permitting, and construction.
Get a custom cost estimate →
How long does the entire ADU process take?
From initial design to final inspection, an ADU project usually takes 8 to 14 months. Design and permitting typically take 4-8 months (depending on your local jurisdiction), and actual construction takes another 4-6 months.
Do I need a permit to build an ADU or convert my garage?
Yes, all ADUs and legal garage conversions require building permits. However, recent state laws have streamlined the permitting process, requiring local agencies to approve compliant ADU applications much faster than standard additions.
Are there parking requirements for ADUs?
In many cases, no. If your property is within a half-mile walking distance of public transit, or located within an architecturally and historically significant historic district, parking requirements are waived.
Contact us to check your parcel →
Can I rent out my ADU on Airbnb?
While ADUs are excellent for long-term rentals (30+ days), many cities prohibit using ADUs for short-term rentals like Airbnb to preserve local housing supply. You will need to check your specific city ordinances.
What is the maximum size allowed for an ADU?
State law mandates that cities must allow a detached ADU of at least 800 sq ft, but many jurisdictions permit up to 1,200 sq ft depending on your lot size and whether it is an attached or detached unit.
Can I use my ADU as a commercial office or retail space?
ADUs are zoned for residential use. While they make perfect home offices or private creative studios for personal use, you generally cannot run a commercial retail business with foot traffic out of an ADU.
Will building an ADU trigger a reassessment of my property tax?
Building an ADU will not trigger a full reassessment of your primary home. Only the newly constructed value of the ADU itself is assessed and added to your existing property tax bill.
What are the best ways to finance an ADU project?
Common financing options include Home Equity Lines of Credit (HELOC), cash-out refinancing, renovation loans (like Fannie Mae Homestyle), and specialized ADU construction loans that consider future rental income.
Book a free feasibility call →
How does an ADU affect my homeowners insurance policy?
You will need to notify your insurance provider to update your policy. The ADU will be covered as an 'other structure' or an 'appurtenant structure,' which usually results in a moderate increase in your premium to cover the replacement cost.
Can my HOA block me from building an ADU?
In most cases, no. State legislation has made it illegal for Homeowners Associations to ban or unreasonably restrict the construction of an ADU on single-family lots, overriding existing restrictive covenants.
Do I need separate utility connections for my ADU?
It depends. Attached ADUs and garage conversions often share utilities with the main house. Detached ADUs may require separate utility connections (water, sewer, power), which can involve additional connection fees.
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DIRECT CONTACT
ADU & Garage Conversion Builder in San Diego County
Bernal Builders, Inc. designs and builds detached ADUs, attached ADUs, garage conversions, Junior ADUs (JADUs), and home additions for homeowners throughout San Diego County. We assist with planning, design coordination, permits, construction, and final inspections.
Request a Free ADU ConsultationCall (619) 540-9618
CSLB License #1047688 • Licensed & Insured • ADU Specialists • Free Estimates
Contact
Phone: 1-(619)-540-9618
Email: [email protected]
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