Building an ADU in San Diego: The Complete Process

Introduction:

San Diego, with its vibrant real estate market and ever-growing demand for housing, has seen a surge in homeowners building Accessory Dwelling Units (ADUs). These secondary units—also known as granny flats, backyard cottages, or in-law suites—are an excellent way to add value to your property, generate rental income, or provide additional living space for family members. However, constructing an ADU is not as simple as putting up a new shed in the backyard. There are specific regulations, permits, and processes that homeowners must follow to ensure their ADU complies with local building codes and zoning laws.

This comprehensive guide will walk you through the complete process of building an ADU in San Diego, from understanding what an ADU is to the benefits of building a permitted unit, and even answering common questions about the process.

What is an ADU?

An Accessory Dwelling Unit (ADU) is a secondary, self-contained housing unit located on the same lot as a primary residence. ADUs can vary in size and design, but they typically include a living space, kitchen, bathroom, and a separate entrance. They can be:

• Detached ADUs: Standalone structures separate from the main house.

• Attached ADUs: Built as an extension of or attached to the existing house.

• Garage Conversions: Repurposing an existing garage into a livable unit.

• Junior ADUs (JADUs): Smaller units, often within the main house, like a converted bedroom or basement.

These units provide versatile housing solutions, whether you need extra space for family members, want to generate rental income, or are looking for a private home office.

Check Attached and Detached ADU Permits in California

The Complete Process of Building an ADU in San Diego

Building an ADU in San Diego requires navigating various steps, from planning and design to obtaining permits and completing construction. Here’s the breakdown of the step-by-step process:

1. Check Zoning Regulations

Before you get started, it's essential to ensure your property is eligible for an ADU. San Diego has specific zoning laws that govern where ADUs can be built. Generally, ADUs are allowed in most residential zones, but the following factors may affect your eligibility:

• Lot size: There are minimum lot size requirements.

• Setbacks: The distance between the ADU and your property line must meet specific standards.

• Height restrictions: Some areas may have limits on how tall your ADU can be.

• Parking requirements: New ADUs in San Diego often don’t require additional parking spaces, but this can depend on your location.

To get the most accurate information, contact San Diego’s Development Services Department or consult with a local zoning expert.

2. Design Your ADU

Once you've confirmed your property’s eligibility, the next step is to design the ADU. Whether you’re converting a garage or building a new structure, it’s important to work with an architect or contractor who is experienced in ADU design and construction. The design should take into account:

• Size and layout: The unit must comply with San Diego’s minimum and maximum size restrictions.

• Energy efficiency: California encourages sustainable construction practices, so energy-efficient designs may help reduce long-term costs.

• Aesthetic considerations: Your ADU should blend with the existing structure, and it must adhere to architectural guidelines set by the city.

3. Submit Permit Applications

Building an ADU requires several permits to ensure the project meets all local building codes and safety standards. In San Diego, the primary permit you will need is the Building Permit. Depending on your project, you may also need additional permits for:

• Electrical work

• Plumbing

• Mechanical systems (HVAC)

You’ll submit your permit application to the Development Services Department (DSD), which will review your plans for compliance with local zoning and building codes. The approval process can take anywhere from a few weeks to a few months, depending on the complexity of your project.

4. Construction and Inspections

Once your permits are approved, it’s time to begin construction. During this phase, the city will conduct several inspections, including:

• Foundation inspections

• Electrical, plumbing, and mechanical inspections

• Final inspection to ensure the ADU meets all building codes

Make sure your contractor is familiar with San Diego's ADU regulations to avoid delays.

5. Final Approval and Occupancy

After your ADU passes all inspections, the final step is receiving your Certificate of Occupancy. This certificate means your ADU is officially ready for use, whether as a rental unit, guest house, or personal living space. Don’t forget to update your property insurance to include the new ADU, as it is now a separate dwelling on your property.

Learn more about How to Get an ADU Permit in California

Benefits of Building a Permitted ADU in San Diego

Building a permitted ADU offers numerous advantages. Here are some of the key benefits:

1. Increased Property Value

A permitted ADU can significantly increase your property’s value. In a market like San Diego, where demand for housing is high, having an additional living unit can make your property more attractive to buyers.

2. Rental Income

One of the most common reasons homeowners build ADUs is to generate rental income. Whether you rent the ADU long-term or use it as a short-term vacation rental, it can provide you with a steady source of passive income, helping you cover your mortgage or boost your savings.

3. Housing for Family or Friends

If you need additional space for aging parents, adult children, or visiting relatives, a permitted ADU offers an ideal solution. It provides a private, self-contained living space that can be tailored to your family’s needs.

4. Tax Benefits

Owning and renting out an ADU could potentially qualify you for tax deductions related to rental income. Be sure to consult with a tax professional to take advantage of any available incentives.

5. Environmental Impact

Many ADUs are built with sustainable materials and energy-efficient systems, making them an environmentally friendly option for homeowners looking to reduce their carbon footprint.

6. Contribution to the Housing Crisis

California’s housing crisis has made affordable housing options in cities like San Diego increasingly scarce. By building an ADU, you’re contributing to the solution by increasing the number of available homes in the region.