San Diego ADUs, designed and built by one team.

An ADU is a complete independent living unit on the same lot as a single-family home: a bedroom, a bathroom and a kitchen area, with its own entrance. It can be attached to the house or detached. Every ADU must be at least 220 square feet and no larger than 1,200 square feet; an attached ADU is also capped at 50 percent of the main home's floor area. A junior ADU, or JADU, is built inside the existing home, may not exceed 500 square feet, and needs a functional kitchen or a shared one with a cooking appliance, a prep counter and storage cabinets. One ADU is allowed on a residentially zoned lot with an existing or proposed single-family dwelling; a lot that already has guest quarters cannot add another, but those quarters can often be converted into a legal ADU with a permit.

A detached ADU is a separate building, usually in the backyard. Its size is not limited by the main house, it offers the most privacy, and it is the choice for a rental or for parents who want their own front door. An attached ADU shares a wall with the house but is internally separate, with its own entrance, bath and kitchen; it offers moderate privacy and easy access, and it is capped at half the main home's floor area. Converting an existing structure, a garage, an attic, a basement or a lower level, uses the foundation and roof you already have, which saves time and money and may let you reuse the plumbing and electrical that already run through the house. An ADU above a garage or carport keeps the parking and adds a view; a second-story ADU adds a whole independent level to a one-story home. Your designer walks the lot with you and tells you which one your property and the rules allow.

New ADUs must meet the required front yard setback and a minimum four-foot setback from the side and rear lot lines; an ADU built above a permitted detached accessory structure keeps the same four-foot rule. A detached ADU is limited to 25 feet in height. An ADU provides one parking space, which may sit within the setbacks and as tandem parking in the existing driveway, and no parking has to be replaced when a garage, carport or covered parking is demolished or converted to build the ADU. ADUs can be rented, but not for less than 30 days, and they cannot be sold separately from the primary residence. The fire department confirms fire setbacks, and the plot plan shows the floor area of both units. Our architects handle all of it; always confirm the details for your lot with the city or the county, which is what we do on every project.

Three state laws took effect on January 1, 2025. Senate Bill 1211 lets multifamily properties build up to eight detached ADUs, as long as the ADUs do not outnumber the existing units on the lot (it does not apply to single-family homes). Assembly Bill 2533 gives unpermitted ADUs built before January 1, 2020 a clear path to legalization: a permit cannot be denied for minor building code violations unless the unit is substandard, and no impact or utility connection fees apply unless safety requires them. Senate Bill 1077 requires the Coastal Commission to publish guidance by July 1, 2026 so that cities simplify ADU permitting in the coastal zone, which matters in La Jolla, Del Mar and Pacific Beach. Owner-occupancy requirements are gone, so an ADU can be rented freely. Our 2025 ADU guide below covers each one in detail.

It depends. Under the American National Standard for single-family residential buildings, a finished area that is not connected to the main residence by a finished hallway or stairway must be listed separately, the ceiling must be at least seven feet high to count as livable space, and if you have to leave the house to enter the structure it cannot be included. A casita that is attached to the main house and entered from inside may be included. The standard is voluntary, so an appraiser or agent who does not use it may count your ADU in the total. Either way, a permitted ADU adds value to the property.

You can, but it is far more complicated than it sounds. San Diego County requires an Owner-Builder Declaration to issue the permit, which puts the liability on you and clears your homeowner's insurance of covering injuries on the job. Anyone who helps you on a project worth more than $500 is legally your employee, which means disability insurance, unemployment, withheld taxes and a state and federal EIN. If you sell, future owners can hold you liable for injuries and damage caused by the construction. And a detached ADU is a small house: new foundation, walls, plumbing, electrical, heating and cooling and a separate roof. We deliver ADUs quickly and efficiently so no permit expires and no inspection has to be repeated, and nothing on your lot is cookie-cutter.

Yes. Kaminskiy Design and Remodeling is a fully licensed and insured California contractor, license #922807, in business in San Diego since 2005. We are members of the BBB, NARI, the U.S. Chamber of Commerce, CACM and CAI, and every technician goes through extensive background and screening checks before working in your home.