Buellton restricts the size of secondary housing units

The Buellton City Council decided to restrict the size and height of accessory dwelling units at a meeting on May 8.

An accessory dwelling unit (ADU) is a completely independent residence with its own kitchens and bathroom, Associate Planner Cara Miralles told the council. She said ADUs can be attached to the main house or detached as standalone units.

In 2022, a California Department of Housing and Community Development review found flaws in some restrictions outlined in Buellton’s ADU ordinance, which was last updated in 2020. This led Buellton to devote a section of its general plan housing element update to fixing its ADU ordinance in May 2023. In April, the Buellton Planning Commission recommended changes for the City Council to pass so that ADU policy could meet state standards. 

The City Council chose to limit the maximum square footage to 850 for one bedroom and 1,000 for multi-bedroom attached ADUs. Detached ADUs are currently limited to 1,200 square feet, Miralles said.

Both of the city’s existing preapproved designs would fit within the size restrictions, according to Miralles. She said the Planning Commission didn’t recommend further restricting size if a detached ADU is combined with others on the same property.

The council also adopted the commission’s recommendation limiting attached and detached ADUs to a maximum height of 25 feet and detached ADUs combined with an attached ADU or junior ADU to 18 feet. The 25-foot maximum height for ADUs allows attached second story additions and ADUs above detached first-floor garages. 

Junior ADUs, unlike ADUs, must be entirely within a single-family home, Miralles said. She said they can consist of no more than 500 square feet and have their own kitchen but share a bathroom with the main house. 

Miralles said garages are not counted in the floor area for an ADU. This gives homeowners a much larger area to work with since the average one-car garage is about 240 square feet. Hypothetically, Miralles said, this would allow someone—if they wanted to—to build a 1,200-square-foot second-story detached ADU over a 720-square-foot three-car garage. 

Miralles said there hasn’t been an instance she’s aware of when the city told someone that they couldn’t build a detached ADU based on size. She said there’s been one 1,200-square-foot detached ADU built in the last seven years and the average studio apartment size in town is 570 square feet.

“This is hard to do by setting policy,” City Councilmember Hudson Hornick said. “This is something that will be on a case-by-case basis. We have a Planning Commission for a reason. … I’m ready to stick to [their square footage guidelines].”

This article appears in May 15-25, 2025.