Building an ADU in San Diego: A Step-by-Step Guide

What is an ADU?
An Accessory Dwelling Unit (ADU) is a supplementary residential house constructed on an existing property alongside the primary residence. ADUs are smaller than the main house and are designed for various purposes.
Benefits of an ADU
There are multiple benefits of an ADU, such as:
- It is a source of additional income.
- It allows guests to stay with you without disturbing your privacy and allowing the required privacy to your guests.
- It is a great medium to ensure living as a multi-generational family. Elderly dependents can be close while being independent.
- It increases the value of a property.
- It allows for low-cost housing in urban areas.
Permit Process of an ADU
California has clear guidelines for ADU construction in San Diego. For example, an ADU must not exceed 800 square feet in size or 16 feet in height. Then there are other considerations considering parking, utilities, etc. You must learn about the laws or allow an ADU builder in San Diego to do it.
If your ADU design complies with all local rules, you don’t need to apply for a traditional building permit, you can simply submit your building plans for fast-track approval. A qualified ADU builder can help streamline this process.
Construction Phases of an ADU
The construction phase of an ADU can be divided into 4 phases.
- Pre-Development: It is when the idea of building an ADU comes to your mind, and you consider your options, budget, and the type of property you want to create.
- Design Development: Work closely with an ADU design build expert in San Diego to create a plan that meets your needs and align with local design guidelines. The design guidelines issued by the authorities must be kept in mind.
- Permit Stage: If you have a design that ticks all the right boxes, then it will be a smooth stage. You need to submit your building plan and get approval.
- Construction Stage: There is not much for you to do but admire your dream becoming a reality. You can offer your opinions and your preferences about the material and design.
Timeline and Budgeting to Build an ADU
Usually, the ADU construction takes 4-5 months, but the size and the detailing you want for your property will decide the timeline. Based on the designs, your builder can give you an accurate estimate.
As for budgeting, the cost of building an ADU in San Diego ranges from $100,000 and $300,000. $100,000 and $300,000. But you must consult your ADU builder for an accurate cost.
Things Needed for Designing Your Dream ADU
Planning to build your dream ADU? Here’s what you’ll need to consider:
- Check if your property can accommodate an ADU
- Ensure compliance with local zoning and ADU checklist San Diego requirements
- Adherence to regulatory standards
- Utility connections
- Adherence to design guidelines
- Fire regulations
Key Considerations while building an ADU in San Diego
Parking
Parking rules have been changed in San Diego. No parking is required for the ADU if it is close enough to public transit. If you do not have a garage, you can use the uncovered spot in the driveway for the main house parking. As for an ADU, you need a parking slot if the ADU is within one and a half miles of public transit, such as a bus.
Zoning Requirements
Your property must comply with the zoning laws set by the San Diego Department of Building and Safety. This affects where and how your ADU can be built.
Maximum Permitted Size
The maximum size of an ADU unit can be up to 800 square feet. The height of an ADU should always be below 16 feet.
No Permission Required
No building permit is required from the city council, neighbors, or anyone else if your building plan adheres to the rules. You can submit it directly to the department and obtain approval.
Cost-Effective Way to Build an ADU: Garage Conversion
Looking for a budget-friendly option? An ADU garage conversion in San Diego is one of the most affordable ways to add livable space to your property. If you have an existing garage structure, converting it into an ADU can save significantly on construction costs. Speak with an experienced ADU builder to explore your garage’s potential.
What’s the Difference Between a JADU and an ADU?
A JADU is a smaller version of an ADU with a maximum size of up to 500 square feet, while an ADU is larger. Most JADUs don’t have an ensuite bathroom and share it with the main house. While an ADU has an independent bathroom and kitchen.
Final Thoughts
Whether you’re exploring a garage conversion ADU in San Diego or planning a custom design from the ground up, following the proper steps to building an ADU ensures a smooth and successful project. From initial planning to final construction, work with a professional ADU design and build team to bring your vision to life, on time and within budget.
About Author
Founder & Chief Sales Officer, House to Home
John Hayes is the Founder and Chief Sales Officer of House to Home Design Build Remodel, a leading general contracting firm serving homeowners across North County San Diego.