CARLSBAD — The city of Carlsbad has updated its accessory dwelling unit regulations on size, number, location, and parking to better align with state law.
Under Carlsbad’s new rules, adopted unanimously by the City Council at a Feb. 3 meeting, attached ADUs that add square footage are limited to 50% of the main dwelling’s area or 1,200 square feet, whichever is greater, with a minimum of 800 square feet.
Detached ADUs are now limited to 1,200 square feet on one-family dwelling lots, while ADUs on two- and multi-family dwelling lots are regulated by state law.
One-family lots are limited to a maximum of three units: one junior ADU, or JADU; one converted ADU; and one attached or detached ADU. Existing multi-family lots are allowed a maximum of eight detached ADUs. The new codes do not apply to new projects, which remain limited to two detached ADUs.
ADUs, also known as granny flats or in-law units, may not exceed the number of dwelling units associated with the primary housing unit or units on the property and are subject to the same design standards, including setbacks and height limits. The changes remove the previous one-story maximum requirement.
Additional local code changes specify that when a parking space is demolished in conjunction with the construction of, or conversion to, an ADU, replacement parking is not required, except on lots west of the rail corridor and those bounded by the rail corridor, Interstate 5, Avenida Encinas and Batiquitos Lagoon, according to the city.
The ordinances reflect recent state laws, including Senate Bills 477 and 1211 and Assembly Bill 2533, which took effect Jan. 1, 2025. The updates amend the zone code and local coastal program under Title 21, as well as the municipal code under Titles 6 and 20.
This week’s vote marked the second reading after the measures were introduced the previous week. The ordinances take effect 30 days after adoption.
While ADUs are often considered a relatively quick way to add housing, upfront costs can be a barrier, with permitting fees ranging from $2,000 to $4,000, depending on square footage, according to the city’s FY 2024-25 Master Fee Schedule.
Construction costs typically range from about $10,000 for a simple bedroom conversion to $300,000 for a higher-end companion unit. Many ADUs are exempt from impact fees because they do not meet the square-footage threshold requirement.
To help cut time and costs, the city offers free, preapproved ADU plans that can save homeowners months of planning and design time and thousands of dollars in private architectural fees, according to city information.
Carlsbad’s updates come as North County cities have increasingly relied on ADUs in recent years to expand housing supply under relaxed state rules, with Encinitas promoting permit-ready plans, Del Mar exploring incentives for deed-restricted units, and Vista seeing homeowners add ADUs for family and rental needs.
ADUs aren’t without controversy, however. The Coast News previously reported that garage conversions and additional units can bring tensions over parking, traffic and tenants in single-family neighborhoods.
