Comprehensive Guide to ADU Permits in California for 2026

As the housing crisis continues to plague California, the demand for Accessory Dwelling Units (ADUs) has skyrocketed. The passage of Senate Bill 9 (SB 9) in 2021 has further fueled the growth of ADUs, making it easier for homeowners to build these units on their properties. In this guide, we will delve into the world of ADU permits in California, covering the regulations, types of ADUs, permit costs, required documents, and more.

Introduction - Why ADUs are Booming in California

The housing crisis in California has led to a severe shortage of affordable housing options. To address this issue, the state government has implemented various laws and regulations to encourage the development of ADUs. SB 9, in particular, has played a significant role in promoting the growth of ADUs. This law allows homeowners to build up to two ADUs on their property, regardless of the zoning laws. As a result, ADUs have become an attractive option for homeowners looking to create additional income streams, provide housing for family members, or simply increase their property value.

The benefits of ADUs are numerous. They provide an affordable housing option for low-income families, students, and seniors. ADUs also offer a unique opportunity for homeowners to generate passive income through rental properties. Additionally, ADUs can help to increase the overall value of a property, making them an attractive option for homeowners looking to invest in their properties.

California ADU Regulations Overview

In 2020, California passed a law that allows homeowners to build one ADU and one Junior ADU (JADU) on their property, regardless of the zoning laws. This law has simplified the process of building ADUs, making it easier for homeowners to create additional housing units on their properties. Here are some key aspects of California's ADU regulations:

• State law allows 1 ADU + 1 JADU per lot: Homeowners can build one ADU and one JADU on their property, as long as they meet the required setbacks and parking requirements.
• No owner-occupancy requirement: Unlike previous laws, there is no requirement for the homeowner to occupy the primary dwelling or the ADU. This means that homeowners can rent out both the primary dwelling and the ADU.
• Reduced setbacks and parking requirements: The state has reduced the setbacks and parking requirements for ADUs, making it easier for homeowners to build these units on their properties.
• Ministerial approval: The approval process for ADUs is now ministerial, meaning that it is a streamlined process that does not require a public hearing or a vote by the city council.

ADU Types and Their Permit Requirements

There are several types of ADUs, each with its own set of permit requirements. Here are some of the most common types of ADUs:

• Detached ADU: A detached ADU is a separate structure from the primary dwelling. It can be built on a vacant lot or on a lot with an existing primary dwelling. The permit requirements for a detached ADU are the most complex, as they require a separate foundation, electrical, plumbing, and HVAC systems.
• Attached ADU: An attached ADU is connected to the primary dwelling. It can be built as an addition to the primary dwelling or as a conversion of an existing garage or other structure. The permit requirements for an attached ADU are less complex than those for a detached ADU, as they can share some of the existing systems with the primary dwelling.
• Garage conversion: A garage conversion is a type of ADU that involves converting an existing garage into a living space. The permit requirements for a garage conversion are relatively simple, as they do not require a separate foundation or major electrical, plumbing, or HVAC system upgrades.
• Junior ADU (JADU): A JADU is a type of ADU that is built within an existing single-family dwelling. It can be created by converting an existing bedroom or other space into a separate living unit. The permit requirements for a JADU are relatively simple, as they do not require a separate foundation or major electrical, plumbing, or HVAC system upgrades.

Permit Costs Breakdown

The cost of obtaining an ADU permit can vary depending on the type of ADU, the location, and the complexity of the project. Here is a breakdown of the typical costs associated with obtaining an ADU permit:

• Plan check: $2,000-$5,000 - This is the cost of having the plans reviewed by the building department to ensure that they meet the required building codes and regulations.
• Building permit: $3,000-$8,000 - This is the cost of the building permit itself, which is typically based on the value of the construction project.
• Impact fees: Vary by jurisdiction - Impact fees are fees that are imposed by the city or county to offset the impact of new development on the community. These fees can vary widely depending on the location and the type of ADU.
• School fees: Vary by jurisdiction - School fees are fees that are imposed by the school district to support the local schools. These fees can vary widely depending on the location and the type of ADU.
• Utility connections: $1,000-$5,000 - This is the cost of connecting the ADU to the utility systems, such as electricity, water, and sewer.

Required Documents and Plans

To obtain an ADU permit, homeowners will need to submit a variety of documents and plans to the building department. These may include:

• Architectural drawings: These are detailed drawings of the ADU, including the floor plan, elevations, and cross-sections.
• Engineering plans: These are plans that show the structural, electrical, plumbing, and HVAC systems of the ADU.
• Title 24 plans: These are plans that show the energy efficiency features of the ADU, such as insulation, windows, and HVAC systems.
• Fire sprinkler plans: These are plans that show the fire sprinkler system of the ADU, if required.

Application Timeline

The timeline for obtaining an ADU permit can vary depending on the complexity of the project and the workload of the building department. Here is a general outline of the application timeline:

• Plan check: 4-8 weeks - This is the time it takes for the building department to review the plans and ensure that they meet the required building codes and regulations.
• Corrections and resubmittal: 2-4 weeks - If the plans are not approved, the homeowner will need to make corrections and resubmit the plans for review.
• Final approval: 1-2 weeks - Once the plans are approved, the homeowner can obtain the building permit and begin construction.

Common Permit Pitfalls and How to Avoid Them

There are several common pitfalls that homeowners can encounter when applying for an ADU permit. Here are some tips for avoiding these pitfalls:

• Hire an experienced designer or architect: A professional designer or architect can help to ensure that the plans meet the required building codes and regulations.
• Submit complete and accurate plans: Make sure that the plans are complete and accurate, and that all required documents and information are included.
• Allow plenty of time for the plan check process: The plan check process can take several weeks, so make sure to allow plenty of time for this process.
• Be prepared for corrections and resubmittal: If the plans are not approved, be prepared to make corrections and resubmit the plans for review.

San Diego County Specific Requirements

San Diego County has its own set of requirements and regulations for ADUs. Here are some specific requirements to be aware of:

• Minimum lot size: 5,000 square feet - This is the minimum lot size required for an ADU in San Diego County.
• Maximum size: 1,200 square feet - This is the maximum size allowed for an ADU in San Diego County.
• Parking requirements: 1 parking space - This is the minimum parking requirement for an ADU in San Diego County.
• Setbacks: 5 feet - This is the minimum setback required for an ADU in San Diego County.

Why Work With an Experienced ADU Builder

Building an ADU can be a complex and time-consuming process, especially for homeowners who are not familiar with the regulations and requirements. Working with an experienced ADU builder can help to ensure that the project is completed on time and within budget. Here are some benefits of working with an experienced ADU builder:

• Expertise: An experienced ADU builder will have the expertise and knowledge to navigate the complex regulations and requirements of ADU construction.
• Time-saving: An experienced ADU builder can help to save time and effort by handling all aspects of the construction process, from design to completion.
• Cost-saving: An experienced ADU builder can help to save money by avoiding costly mistakes and ensuring that the project is completed within budget.
• Quality: An experienced ADU builder will ensure that the ADU is built to the highest quality standards, using only the best materials and construction techniques.

Get Started With Your ADU Project Today

If you are considering building an ADU on your property, contact us today to schedule a consultation. Our team of experienced ADU builders and designers can help you to navigate the complex regulations and requirements of ADU construction, and ensure that your project is completed on time and within budget. Don't wait - get started with your ADU project today and take the first step towards creating a valuable and profitable investment property.

Call us now at 555-555-5555 or email us at [email protected] to schedule your consultation. We look forward to working with you to bring your ADU project to life.