San Carlos examining updated ADU policies

With a 3-0 vote — with Chair Jim Iacaponi and Vice Chair Kristen Clements absent — commissioners backed updates to the city’s ADU ordinance, bringing the policy in line with state laws — that took effect earlier this year — and going beyond state guidance in some cases.

Key updates include allowing ADUs to be built below a garage, typically something that would be done on homes built on slopes, and for ADUs attached to a garage to be built outside the garage footprint. Junior accessory dwelling units, or ADUs attached to a home, would also be allowed in unenclosed crawlspaces while language would be removed that prohibits including JADUs in new additions.

Residents would also be allowed to build ADUs with a maximum square footage based on 50% of the footprint of their existing home. Per state law, the city must allow ADUs to be at least 800 square feet and new state law now also permits property owners to encroach on their front lot setback if no other space on the property exists.

The updated ordinance would also allow for accessory units to be built taller in some cases. As proposed, the ordinance would allow the height of attached ADUs to be determined by the base zoning district. While state law requires cities to allow attached ADUs of up to 25 feet, the city’s residential zoning areas would allow units up to 28 feet.

For detached units, state law calls for permitting units of between 18 feet to 20 feet tall when located within a half mile of public transit, 18 feet when proposed as part of a new or existing multifamily building or 20 feet when built with a detached garage. The city currently limits heights to 16 feet.

Commissioners largely supported the updates except for the amendment allowing taller ADUs near transit lines. Commissioner David Roof noted some properties would qualify for the height allowance by being located near a school bus route that runs infrequently and suggested the taller heights be allowed citywide instead.

“It doesn’t fulfill the purpose of wanting to build more along that route because it’s not like somebody who had a job could use that bus. It’s tailored to school kids,” Roof said. “There’s sort of a fairness thing that’s irking me here since those bus lines don’t really meet the reason you have that rule. It’s sort of arbitrary.”

Principal Planner Andrea Mardesich said the language used in the updated ordinance is based on state law and couldn’t be made more restrictive to clarify that school bus routes don’t apply. Instead, she said staff would look into the impacts of using a more generous height policy and would bring that to the council for consideration.

Staff will next bring the updates to the City Council for a vote at which point the document will be submitted to the state Department of Housing and Urban Development for review. HUD may provide recommendations which could lead to some changes, Mardesich said.

“I absolutely expect we’ll be coming back with changes more than once in the future,” Mardesich said. “We don’t want to be … married to all these standards and say this is it. It’s definitely a living document that will likely be changed as we see it implemented as well.”