San Diego is experiencing a surge in the popularity of ADUs Accessory Dwelling Unit (AKA granny flat, in-law unit, casita, or second unit) thanks to their flexibility and potential to alleviate housing shortages. Whether you’re considering adding a rental unit, guest house, or a space for family, building a San Diego ADU can significantly enhance your property’s value and functionality. Here we'll walk you through everything you need to know about ADUs in San Diego County, from understanding what they are to navigating the permit process and estimating costs.
What is an ADU?
An Accessory Dwelling Unit (ADU) is a secondary housing unit on a single-family residential lot. ADUs can be attached to the main home, detached as a separate structure, or converted from existing spaces like garages or basements. They offer a great solution for additional living space, rental income, or housing for family members.
Types of SAN DIEGO ADUs You Can Build
Detached ADU: A standalone unit separate from the main house. Here you can see Butterfly ADU in La Mesa
Attached ADU: A unit that is attached to the main home, sharing at least one wall. Here you can see La Jolla ADU.
Garage Conversion: Converting an existing garage into a livable ADU. Garage Conversion can be fun!! Here you are seeing Carlsbad Garage Conversion.
Basement/Attic Conversion: Turning unused basement or attic space into an ADU. And in this case the ADU has a lot of light like in our Underground ADU in La Jolla
Junior ADU (JADU): A smaller unit, often within the walls of the existing home, typically around 500 square feet. San Diego Granny Flat is an example.
Multiple ADUs: Did you know that in San Diego, you can build multiple ADUs in a single-unit property?
Steps to Get a City Permit for Your ADU
Building an ADU in San Diego involves several steps, and navigating the city's permit process can be complex. Here’s a simplified breakdown:
Research Local Regulations: Familiarize yourself with San Diego County’s city zoning, building codes, and fees. Each neighborhood may have different rules regarding ADUs. Knowing the regulations can save owners hundreds of dollars. In our case, for La Mesa Granny Flat we intentionally submitted the project the day after traffic fees/taxes were reduced 50%, and the ADU is 749 s.f. to avoid impact fees ($0 for ADUs under 750 s.f.). Here are some regulation Resources:
San Diego ADU: Municipal Code, Bulletin 400, Permit Processing Timeline.
Design Your ADU: Work with an architect, designer, or engineer to design an ADU that meets your needs, takes advantage of your plot, designs a creative space, and is cost-effective. And, of course, the ADU complies with local regulations. In Encinitas ADU the client had a small budget so we designed an orthogonal geometry with low-cost materials.
Submit Permit Application: Once your design is ready, your architect will submit your permit application to the City or County.
Plan Review: The city will review your plans for compliance with building codes, zoning laws, and other regulations and replies need to be done.
Obtain Permit Approval: After any required revisions, you’ll receive approval and can begin construction.
Select a general contractor: Work with your architect, designer, or engineer to find the best contractor that fits your requirements.
Inspections: Throughout the construction process, the city will conduct inspections with the general contractor to ensure the ADU is built to code.
Final Approval: Once construction is complete and all inspections are passed, you’ll receive a final approval to legally occupy the ADU.
Range of Prices for ADUs in San Diego (HARD COST)
Garage Conversion: $90,000 - $180,000. For a budget breakdown, check this article about our Carlsbad Garage Conversion on Dwell.
Junior ADU: $100,000 - $170,000
Attached ADU: $150,000 - $350,000
Detached ADU: $250,000 - $400,000+
Prices can vary depending on the size, materials, finishes, and site conditions (hard cost). Factor in additional costs for design, permits, utilities, and landscaping (soft cost).
Benefits of Building an ADU
Rental Income: Rent out your ADU to generate a steady income stream. In our Quebrada ADU, the owners are living in the brand new ADU, and they are renting the main house.
Sustainable Living: ADUs often utilize sustainable building practices, reducing the environmental footprint.
Flexible Living Arrangements: Use the ADU for aging parents, adult children, or guests. In our San Diego Garage conversion you can do multiples activities in the same space. Flexiblity is the key to enjoy a small space in all the ways possible.
Increased Property Value: ADUs can significantly boost your property’s market value.
Challenges to Consider
Zoning Restrictions: Not all areas in San Diego allow ADUs, and some have strict zoning laws.
Construction Costs: Building an ADU in San Diego County can be expensive, so it’s important to design a budget-conscious ADU. Here is where your architect, designer, or engineer has a key role in your project. There are different factors to have a beautiful and contemporary ADU without breaking the bank:
Be strategic with the foundation and structure.
Use sustainable materials that are both cost-effective and durable.
Optimize natural light to enhance the space, reducing the need for expensive finishes.
Prioritize a minimalist design with clean lines and multipurpose spaces.
Focus on essential amenities and keep the design simple to minimize construction costs.
Permit Delays: The permitting process can be time-consuming and complex.
SUSTAINABILITY CONSIDERATIONS
We believe that sustainability should be the core of our architectural practice in San Diego. We believe in creating spaces that are not only beautiful but also environmentally responsible. Here some example
Energy Efficiency: Sustainable ADUs reduce energy consumption and utility costs and lessen environmental impact.
Water Conservation: Incorporating water-saving features like low-flow fixtures and drought-resistant landscaping is crucial in a drought-prone region.
Long-Term Durability: Using sustainable, high-quality materials ensures the ADU's longevity, reducing the need for future repairs and replacements.
Healthy Living Environment: Eco-friendly materials and good ventilation create a healthier indoor space, improving air quality and comfort.
Increased Property Value: Sustainable ADUs appeal to environmentally conscious buyers, enhancing property value and marketability.
Conclusion
Building an ADU in San Diego is a smart investment offering both financial and personal benefits. By understanding the process, design, costs, and options available, you can create an ADU that enhances your property and meets your unique needs. Follow us @moderngrannyflat and here on the blog for more in-depth guides, design ideas, and tips to make the most of your ADU project.