Building an Accessory Dwelling Unit (ADU) in San Diego has never been more beneficial, or more achievable, than it is today. Whether you’re looking to generate rental income, create a comfortable space for aging parents, support adult children, or simply increase your property’s long-term value, an ADU offers a powerful combination of financial return and lifestyle flexibility.
Unfortunately, you might feel overwhelmed when you start researching ADUs. There are permits, design requirements, construction timelines, utility upgrades, and a constantly evolving set of state and local regulations that can make the process seem complicated. You’re in luck, though, because that’s exactly where we come in at GDC Construction.
As a fourth-generation San Diego ADU contractor and builder, we’ve seen the city’s housing landscape shift over decades. Today, the ADU-friendly environment is one of the greatest opportunities homeowners have ever had. With recent California laws easing restrictions and streamlining approvals, adding an ADU is no longer a pipe dream. Our team specializes in turning what feels complicated into a clear, streamlined, and confident path from concept to completion.
If you’re exploring ways to unlock the potential of your property, you’re in the right place. Here’s what you need to know about building an ADU and how we can help.
Why ADUs Make Sense in San Diego Right Now
San Diego’s housing market has reached a point where traditional expansion, either through purchasing a larger home or adding square footage, often feels impractical. However, the limited inventory, high home prices, and strict zoning in many neighborhoods make ADUs an accessible way to grow your space and income, and even create long-term wealth.
California continues to encourage ADU development, and San Diego has embraced the movement more than most cities. That means fewer barriers, faster approvals, and more opportunities for you to enhance your property.
The Income Opportunity You’re Sitting On
San Diego’s rental market remains one of the strongest in the country, and demand for well-built 1- and 2-bedroom units is on the rise. Across neighborhoods, a one-bedroom ADU can rent between $2,000 and $3,200 per month, while two-bedroom ADUs can rent for $2,800 to $4,500 per month, depending on location, finishes, and amenities. Those figures make an ADU an attractive rental property and a smart part of many families’ real estate investments.
If you’re in coastal neighborhoods like Pacific Beach, Ocean Beach, and Point Loma, you may have opportunities for even higher rents. Even if you’re not on the coast, though, more central or inland neighborhoods like North Park, Clairemont, Serra Mesa, and Scripps Ranch can still generate some great returns.
Along with the long-term nature of many ADUs, you may want to consider short-term or mid-term rentals, too. Local regulations vary, of course, but vacation renting may be possible in certain areas with proper permitting.
Multi-Generational Living Without Losing Your Sanity
San Diego’s high cost of living means multi-generational housing is popular. Because of that, families are turning to ADUs as a way to keep loved ones close without sacrificing anyone’s privacy or independence.
For example, ADUs can serve as:
- A comfortable place for aging parents to live near family while maintaining autonomy
- A starter home for adult children priced out of the city’s rental market
- A flexible space for returning college students
- A long-term guest suite
- A quiet home office separate from the main house
The magic of an ADU is that it creates a connection without crowding and provides multiple options for property owners like you to keep family close or build future wealth.
Property Value and Future Flexibility
In a market like San Diego, square footage is valuable, and that goes double for usable, income-producing square footage. An ADU can significantly increase your property’s appraised value, making your home more attractive to future buyers.
Not only that, but ADUs equal adaptability. You might rent the space today, house family members in a few years, convert it to an office or studio later, and eventually use it to supplement retirement income.
Types of ADUs We Build Throughout San Diego
No two properties, or families, are the same, which is why ADUs come in many shapes and sizes. At GDC Construction, we design and build a wide range of ADU types, tailored to each homeowner’s lot, zoning, goals, and architectural style. Our ADU designers help match form and function, and our experienced ADU builders execute with precision.
ADUs in San Diego typically range from 400 to 1,200 square feet, though a Junior Accessory Dwelling Unit (JADU) may be smaller. No matter what you’re imagining, there are options for almost every property, including evaluation of a prefab ADU if it fits your site and goals.
Detached ADUs (Backyard Homes)
Detached ADUs are the most popular option for homeowners who want a truly independent living space. These standalone homes typically range from 600 to 1,200 square feet and include everything a traditional home would, including a private entrance, kitchen, bathroom, bedrooms, and outdoor living areas.
Detached ADUs work especially well in neighborhoods with larger lots or alley access. They offer maximum privacy for both the main house and the ADU residents, making them ideal for long-term tenants, family members, or visitors.
Garage Conversion ADUs
Garage conversions are often the most cost-effective ADU option because they repurpose existing square footage. Most garages convert into 350 to 500 square feet of living space, depending on whether the garage is attached or detached.
San Diego’s updated parking rules significantly reduce or eliminate parking replacement requirements in many cases, which makes conversions even more attractive.
Attached ADUs and Junior ADUs (JADUs)
Attached ADUs extend the main house with a new addition or convert existing interior space. They can range anywhere from 400 to 1,200 square feet, depending on lot conditions and desired layout.
JADUs, meanwhile, are under 500 square feet and must be created from existing living space. They typically share utilities and may share a bathroom with the main house, but they require a private entrance and an efficient kitchen.
Above-Garage ADUs
Above-garage ADUs are perfect for homeowners who want additional square footage without sacrificing yard space. They offer increased privacy and often have excellent natural light and views in neighborhoods like Point Loma or Pacific Beach.
Because structural reinforcement is required, above-garage units can be more complex, but the payoff is a spacious, private ADU that maintains your property’s existing footprint and keeps your outdoor space intact.
Navigating San Diego’s ADU Regulations (We Handle This Part)
The biggest hesitation many homeowners have about ADUs is the permitting and compliance process. The good news is that California and San Diego laws have become significantly more ADU-friendly, so it’s easier and faster to build than ever before.
Still, the process involves multiple layers of regulation, and that’s where we come in. We’ll handle everything from feasibility to permitting, so your project can move smoothly and stay compliant.
Recent California Laws That Actually Help You
Updated state regulations have removed many of the barriers that used to complicate ADU construction. Laws such as SB 9, SB 10, and various ADU-specific statutes have helped by reducing minimum setback requirements, increasing allowable height, streamlining approvals, eliminating many owner-occupancy requirements, and allowing more flexibility for lot splits and density.
San Diego Specific Requirements
San Diego’s municipal code adds another layer of nuance, but it’s also become more supportive. Some of the local factors we’ll evaluate for you include whether owner-occupancy is required (often it isn’t), any parking requirements, especially for transit-adjacent lots, and the lot size and maximum ADU square footage. Along with those areas, we’ll help with the evaluation of coastal zone considerations, height limits, and design compatibility requirements. This is where working with San Diego ADU builders who understand local nuance makes a real difference.
HOA and Historic District Considerations
If you live in an HOA community or a historic district, ADUs are still possible, but they generally require additional steps. HOAs can’t prohibit ADUs, though they can set aesthetic standards, and historic districts may require sensitive design approaches. We have extensive experience navigating both and can ensure your ADU respects community guidelines without compromising functionality or style.
The Hidden Costs Other ADU Contractors Don’t Mention
At GDC Construction, transparency is one of our core values. While some leading ADU builders in San Diego gloss over or downplay the full scope of costs, we believe informed homeowners make the best decisions. Beyond the base construction budget, here are common costs you should be aware of upfront.
Beyond Construction: Utility Connections and Upgrades
Every ADU needs access to power, water, sewer, and sometimes gas. Depending on your property’s existing systems, you may need:
- Electrical panel upgrades ($2,000–$5,000)
- New sewer laterals or rerouting ($4,000–$12,000)
- Water line upgrades (varies widely)
- Gas line extensions (if applicable)
Not every property needs all these upgrades, but understanding them early prevents surprises.
Permit and Design Costs
Permit and design fees in San Diego typically include:
- Architectural drawings
- Structural engineering
- Civil engineering (if needed)
- Title 24 energy compliance
- City permit fees
These often total 10 to 20% of the overall project cost, depending on complexity. Because we offer in-house design, we can streamline cost and coordination, a hallmark of the best ADU builders.
Site Preparation and Access
San Diego properties can present unique challenges, such as:
- Steep slopes
- Narrow side yards
- Large trees
- Limited access for construction equipment
Grading, tree removal, temporary fencing, and protecting landscaping might add to your project’s costs, and identifying items early helps you budget accurately.
Our ADU Process: From Idea to Income
At GDC Construction, we’ve created a clear, efficient ADU process that keeps you informed and moves projects along.
Site Evaluation and Feasibility
We’ll begin with a preliminary assessment, often at no charge, to determine what your property can support. This includes reviewing setbacks, lot size, utility access, slope and grading, parking, and easements.
Design and Pre-Approval
Next, our in-house design team, led by Brandy Dewhurst, develops a design tailored to your goals, budget, and architectural style. We’ll create permit-ready plans so you can visualize the finished space.
Permitting and Approvals
Permitting is often the longest phase, but recent law changes have significantly improved approval timelines. Most ADUs in San Diego are now reviewed within 60 to 90 days, depending on complexity, and we’ll manage every aspect of the permitting process.
Construction and Quality Control
Once permits are issued, construction can begin. A typical ADU takes three to six months, depending on scope and site conditions. During construction, you can expect us to maintain a clean, organized work site, minimize disruptions for residents, and use the same quality standards as custom home builds. Additionally, we’ll provide transparent updates through Buildertrend and ensure every detail meets our high standards.
ADU Design Ideas That Work in San Diego
San Diego’s climate and architectural diversity offer endless possibilities for ADU design, with some great styles homeowners love.
Modern Coastal Studios
Clean lines, sun-filled rooms, and seamless indoor-outdoor living define modern coastal ADUs. They often include sliding glass doors, light wood tones, neutral palettes, breezy, open layouts, and covered outdoor patios. Designs like these are especially popular in beach communities like Ocean Beach, Carlsbad, and Encinitas.
Spanish and Mediterranean Casitas
Many San Diego neighborhoods feature classic Spanish and Mediterranean architecture. For these homes, a casita-style ADU blends beautifully with the main house. These ADUs can include white or cream stucco, clay tile roofs, arched doorways, wrought iron accents, and courtyard-style entries. You might want a perfect match to your home, or a complementary style that maintains harmony without duplicating every detail.
Sustainable and Energy-Efficient Designs
Sustainability isn’t just good for the environment. It’s also smart long-term planning. If you’re looking for an energy-efficient ADU option, we can help create one with a solar-ready roof, high-performance windows, a heat pump system, efficient insulation, and low-water landscaping.
All ADUs are required to meet California Title 24 requirements, but going beyond minimum standards can really reduce your operating costs.
Financing Your San Diego ADU Project
Financing an ADU may feel intimidating, but there are more options today than ever before. While we don’t provide financial advice, we’ll help you understand the available pathways so you can make an informed decision.
Construction Loans and HELOC Options
Many homeowners use:
- Construction-to-permanent loans
- Home equity loans
- Home equity lines of credit (HELOCs)
- Cash-out refinancing
Some lenders also now allow projected ADU rental income to be included in qualification calculations, which can make financing more accessible.
CalHFA ADU Grant Program
California offers an ADU grant program that can help you offset pre-construction costs such as design, engineering, and permits if you qualify. The program includes income requirements and funding maximums, and more details can be found by visiting the California Housing Finance Agency website.
Return on Investment Timeline
ADUs typically pay for themselves through monthly rental income, increased property value, long-term flexibility, and reduced family housing costs. With typical San Diego rental rates, you’ll generally see significant ROI within a decade, or even sooner if you’re in a higher-demand neighborhood.
Why GDC Construction for Your ADU Project?
Not all San Diego ADU contractors are created equal. At GDC Construction, we stand out because of our history, our team, and our commitment to building ADUs with the same care and craftsmanship as primary residences.
Four Generations of San Diego Building Expertise
GDC has been building in San Diego for over 70 years, long before ADUs became popular. Our deep understanding of local neighborhoods, design styles, and regulations gives homeowners like you a level of confidence newer San Diego ADU contractors simply can’t match. This generational experience means we know how to anticipate challenges, navigate regulations, and deliver beautiful, lasting results.
In-House Design and Construction Teams
Because we operate as a true design-build firm, everything happens under one roof, including design, engineering, permitting, and construction. That means:
- No finger-pointing between architects and builders
- Faster communication
- More accurate pricing
- A unified vision from start to finish
With Brandy Dewhurst leading design, homeowners get an ADU that is both functional and architecturally cohesive.
We Build ADUs Like They’re Our Own Homes
Some San Diego ADU contractors rush jobs or cut corners to speed production, but we don’t believe in that approach. Every ADU is built with the same standards, craftsmanship, and structural integrity as the custom homes we’ve built for decades, and we maintain a dedicated service department for ongoing support long after construction is complete.
San Diego Neighborhoods Where We Build ADUs
We proudly build ADUs throughout San Diego County, across a wide variety of neighborhoods and lot types.
Coastal Communities
In areas like La Jolla, Pacific Beach, Ocean Beach, and Point Loma, ADUs often involve coastal considerations, but that also means high rental rates. Lots vary greatly, but privacy, views, and design harmony are top priorities.
Central San Diego
Neighborhoods such as Mission Hills, North Park, South Park, and Clairemont offer ideal infill opportunities. Many of these lots are well-suited for detached backyard units or garage conversions, and their proximity to job centers increases their appeal.
Inland Neighborhoods
Scripps Ranch, Rancho Bernardo, Encinitas, and similar areas often have larger lots, and they can be ideal for family-focused ADUs, multigenerational living, or spacious detached units.
Start Your ADU Journey Today
Whether you’re just beginning to explore the idea of an ADU or you’re ready to start designing, we make the process clear, manageable, and exciting. We’re here to answer questions, evaluate your property, and guide you step-by-step.
Free ADU Feasibility Assessment
We offer a no-obligation feasibility check that includes a site review, preliminary design ideas, a zoning and setback evaluation, and a rough cost and timeline discussion. Call us at (858) 551-5222 or use our contact form today to get started and discover what’s possible on your property.
Download Our ADU Planning Guide
Our ADU Planning Guide includes checklists, budgeting tools, design inspiration, and key regulatory insights. It’s a valuable resource for any homeowner considering an ADU and can be accessed by requesting a copy from our team.
Visit Our Office to See ADU Plans and Designs
Our San Diego office features ADU plans, design boards, and sample materials you can explore in person. Visit us at 1031 Silverado Street in La Jolla from 7 am to 4:30 pm Monday through Friday to meet the team, review examples, and get a clearer picture of what your ADU can look like. There’s no pressure and no sales pitch, just education and support from a San Diego ADU contractor you can trust.
