Garage Conversions in San Diego: Transforming Your Space into a Functional ADU

San Diego homeowners are increasingly turning to Accessory Dwelling Units (ADUs) as a way to add more living space, increase property value, and generate rental income. One of the most cost-effective ways to create an ADU is through a garage conversion—a process that transforms an existing garage into a fully functional living space.

With the growing demand for affordable housing and multigenerational living, garage conversions have become one of the most popular ways to maximize underutilized space. Whether you’re looking to create a guest house for the backyard, provide housing for family members, or generate passive rental income, converting your garage into an ADU can be an excellent investment.

In this guide, we’ll explore:

By the end of this guide, you’ll have a clear understanding of how to transform your garage into a fully functional ADU that meets local requirements while enhancing your home’s value and livability.

A garage conversion ADU is one of the fastest and most efficient ways to create additional living space. Unlike new construction, which requires building a separate structure from the ground up, a garage conversion repurposes an existing structure, making it a streamlined and budget-friendly option.

Here are some key benefits of transforming your garage into an ADU:

Because the foundation, walls, and roof of a garage are already in place, garage conversions typically require less material and labor than building a new ADU from scratch. This means that homeowners can achieve significant cost savings while still adding a high-quality living space to their property.

Adding an ADU to your property increases square footage, which can raise the market value of your home. Many homebuyers today are looking for properties with ADUs because of their flexibility—whether for renting, hosting guests, or accommodating family members.

With San Diego’s high rental demand, a converted garage ADU can serve as a long-term rental unit or even a short-term vacation rental (depending on local regulations). A well-designed 2 bed 2 bath ADU plan can attract tenants looking for affordable yet spacious housing in prime locations.

More families are choosing multigenerational living arrangements, where aging parents, adult children, or extended family members share a property while maintaining independent living spaces. A garage conversion ADU offers a private and comfortable solution for keeping loved ones close while ensuring personal space.

Instead of tearing down or expanding your home, a garage conversion makes use of an existing structure, reducing waste and minimizing the environmental impact of new construction. Many homeowners also integrate eco-friendly features, such as solar panels, energy-efficient windows, and water-saving appliances, to make their ADU more sustainable.

Compared to building a new detached ADU, a garage conversion typically requires less permitting time and fewer structural modifications, allowing homeowners to complete the project faster and more efficiently.

Once your garage is converted into an ADU, the possibilities for how you use it are endless. Here are some popular ways homeowners in San Diego are utilizing their converted spaces:

A garage conversion ADU can serve as a long-term rental unit, providing a steady stream of passive income. Whether you opt for a studio, 1-bedroom, or even a 2-bedroom ADU floor plan, the added rental income can help offset mortgage costs and increase your return on investment.

If you frequently have friends and family visiting, a guest house for your backyard is a great way to provide comfortable accommodations without disrupting your main living space. Garage conversions are also perfect for aging parents who want to stay close to family but maintain independence.

With the rise of remote work, many homeowners are looking for quiet, dedicated workspaces. A converted garage can be transformed into a home office, art studio, music room, or yoga retreat, allowing you to separate work and home life effectively.

As housing prices in San Diego continue to rise, more young adults are living at home longer. A garage conversion ADU provides a private living space for adult children, giving them independence while still staying close to family.

If permitted by local regulations, some homeowners choose to use their garage conversion ADU as an Airbnb or short-term rental. San Diego’s thriving tourism industry makes this a potentially lucrative option for homeowners in prime locations.

Before starting your garage conversion, it’s important to understand San Diego’s ADU laws to ensure your project meets local requirements.

In San Diego, homeowners can legally convert their garage into an ADU if their property is located in a residentially zoned area. Most single-family and multifamily properties qualify for ADU development.

Key regulations include:

To legally convert a garage into an ADU, you’ll need to obtain permits from the City of San Diego’s Development Services Department. The process typically involves:

Working with an ADU architect in San Diego or an ADU builder San Diego team can help streamline this process, ensuring all permits and regulations are handled correctly.

Once you’ve confirmed that your garage conversion is feasible and permitted under San Diego’s ADU regulations, the next step is to focus on design and layout. A well-planned garage conversion ADU should be functional, efficient, and visually appealing while meeting the needs of its intended use—whether it’s a rental unit, guest house, or home office.

At OneStop ADU, we specialize in designing high-quality ADUs that blend seamlessly with your existing property. Let’s explore the key design considerations, floor plan options, and customization features to help you create the perfect garage conversion ADU.

The floor plan is the foundation of your ADU’s functionality. Since garages come in different sizes, selecting the right layout is crucial to making the most of your available space. Whether you have a one-car, two-car, or even a detached garage, there are multiple ADU floor plan options to consider.

Here are some popular garage conversion ADU floor plans:

A studio ADU is perfect for small garages or homeowners who want a compact and efficient living space. This layout typically includes:

If your garage is on the smaller side, a 400 sq ft ADU floor plan can maximize space while still feeling comfortable and functional.

A one-bedroom ADU is a great choice for homeowners looking to provide a bit more privacy and separation between living and sleeping areas. This layout often features:

One-bedroom ADUs are ideal for long-term rentals, guest houses, or home offices. If your garage allows for expansion, you can modify a 600 sq ft ADU plan to include more amenities.

For those with a larger garage space or those looking to extend their structure slightly, a two-bedroom ADU can provide even more flexibility. A 2-bedroom, 1-bath floor plan is a popular choice for:

A 2-bedroom ADU floor plan is one of the most versatile layouts, providing a home-like feel while maintaining a smaller footprint than a traditional house.

For those who need a bit more room, 2 bed 2 bath ADU plans can be an option, particularly if you’re considering a slight expansion beyond the garage footprint.

If you have the ability to extend your garage structure, a three-bedroom ADU can offer a full-sized living experience in a compact space. A 3-bedroom 2-bath ADU is perfect for:

With a 1,000 sq ft ADU floor plan, you can incorporate a spacious kitchen, dedicated dining area, multiple bedrooms, and ample storage, making it feel like a standalone home.

Beyond selecting the right floor plan, homeowners can customize their garage conversion ADU to reflect their style, functionality needs, and budget. Here are some key design elements to consider:

Since ADUs typically have smaller footprints, an open floor plan can make the space feel larger and more inviting. Removing unnecessary walls, using light-colored interiors, and incorporating large windows can enhance natural light flow, making the ADU feel bright and airy.

Storage can be a challenge in a garage conversion, so it’s essential to maximize every inch of available space. Consider:

OneStop ADU works with homeowners to integrate clever storage solutions into their ADU designs, ensuring the space remains functional and organized.

Even though an ADU is a smaller living space, investing in high-quality finishes can elevate its appeal. Some popular choices include:

Choosing premium finishes makes the ADU more attractive to potential tenants or guests while ensuring long-term durability.

San Diego homeowners are increasingly prioritizing eco-friendly features in their ADU designs. Consider incorporating:

Not only does this reduce utility bills, but it also makes your ADU more appealing to eco-conscious renters and buyers.

If your garage has access to a backyard or patio, consider incorporating indoor-outdoor elements like:

This approach creates an extension of the living space, making a smaller ADU feel much larger.

Converting a garage into an ADU requires careful planning, expert execution, and compliance with San Diego’s regulations. Working with experienced ADU builders, architects, and contractors can make the process smoother and stress-free.

When selecting an ADU builder in San Diego, look for:

Companies like OneStop ADU specialize in turnkey ADU solutions, handling everything from design and permitting to construction and final inspections.

An ADU architect in San Diego can help ensure your garage conversion is:

By working with an experienced ADU architect and builder, you can ensure your garage conversion project runs smoothly and meets all legal requirements.

Now that we’ve covered the benefits, design options, and key considerations for your garage conversion ADU, let’s walk through the step-by-step process to transform your underutilized garage into a fully functional living space.

Working with an experienced ADU construction company in San Diego—like OneStop ADU—can make this process smoother and more efficient. However, it’s still important to understand each phase so you know what to expect along the way.

Before diving into design and construction, it’s important to evaluate whether your garage is suitable for conversion. Consider the following questions:

Working with an ADU architect in San Diego or a contractor can help assess your garage’s viability, identify necessary upgrades, and determine the best floor plan options.

To legally convert your garage into an ADU in San Diego, you’ll need to obtain permits from the City of San Diego’s Development Services Department.

The permitting process generally involves:

Hiring an ADU builder in San Diego ensures your plans and permits are handled efficiently, reducing delays and ensuring compliance.

Once permits are secured, the design phase begins. You’ll work with an architect or ADU builder to develop a floor plan that maximizes space, comfort, and functionality.

Key design considerations include:

At OneStop ADU, we offer pre-designed ADU models that can speed up the process while allowing for customization.

Before construction begins, the existing garage structure needs to be prepared. This may include:

Your garage conversion ADU will need full utility connections to be functional. This includes:

OneStop ADU works with licensed ADU contractors in San Diego to ensure your ADU meets modern efficiency and safety standards.

Once the structural work is complete, the finishing phase brings your ADU to life. This includes:

For the exterior, homeowners can choose:

By incorporating high-end finishes, your garage conversion ADU will feel like a luxury living space—not just a converted garage.

Before you can legally rent or occupy your ADU, the City of San Diego will conduct final inspections to ensure:

Once your ADU passes inspections, you’ll receive a Certificate of Occupancy, and your new garage conversion ADU will be move-in ready!

Transforming a garage into an ADU can be overwhelming, but working with experienced ADU builders in San Diego can make the process seamless.

At OneStop ADU, we offer:

Whether you need a 600 sq ft ADU plan, a 2-bedroom 1 bath ADU, or a guest house for your backyard, our team is here to make it happen!

If you’re looking to increase property value, generate rental income, or create a multigenerational living space, a garage conversion ADU is an excellent option. By repurposing your existing garage, you can maximize space efficiently while keeping construction costs lower than a new ADU build.

With the right planning, design, and professional team, your garage can become a modern, functional, and high-quality living space.

Ready to convert your garage into a fully functional ADU? Our expert team at OneStop ADU is here to guide you through every step of the process.

Call us today at (858) 290-6286 for a free consultation!

Let’s turn your garage conversion ADU dreams into reality!