News · December 5, 2025 · California's housing department told Los Altos and Saratoga their ADU ordinances on file, from 2020, may be outdated and out of compliance. [1][2]
News · May 11, 2026 · California's housing department told Mountain View its ADU ordinance on file, from 2023, may be outdated and out of compliance. [3]
Planning an ADU in the City of Los Altos, Saratoga or Mountain View? The city's code may not match current state law in places, and the state has asked the city to show it still complies or plan to replace or repeal it.
Does a junior ADU require the owner to live on the property?
Since January 1, 2026, state law says owner-occupancy "shall not be required" when a junior ADU (JADU), a unit built within the walls of the house, has its own bathroom ("separate sanitation facilities") [4]. As published, all three codes require an owner to live on a property with one, with exceptions only for public agencies, land trusts and housing organizations [5][6][7]. That's one gap you can check yourself.
Before you design, ask the city in writing which rules it will apply.
What do the state's letters to the three cities say?
In each letter, HCD, the state housing department, says that given the many changes to state ADU law since the ordinance was adopted, it "may be outdated and out of compliance" [1][2][3]. None says that it is.
Each lists recent changes to state ADU law. Among them: impact fees are barred on an ADU of 750 square feet of interior living space or less, a city has 15 business days to say whether an application is complete, and an ordinance is void if the city misses the state's deadlines to file it or answer HCD's findings [1][2][3]. See our note on the void rule.
Each sets a reply date: January 4, 2026 for Los Altos and Saratoga, June 10, 2026 for Mountain View. The city can explain how its ordinance still complies, or send a plan and timeline to repeal it or adopt a compliant one. If HCD's records are wrong and a newer ordinance exists, HCD asks for that one [1][2][3].
Each also says an ordinance that fails to meet state ADU law is "null and void," so the state's standards apply, and recommends repealing one that doesn't comply [1][2][3].
Have the three cities updated their ADU rules or replied?
Los Altos rewrote its ADU chapter with Ordinance 2024-512, adopted April 30, 2024, newer than the 2020 one in HCD's letter [1][5]. Saratoga's ADU article dates from October 21, 2020, with amendments in April and October 2024 [6]. Mountain View's ADU rules date from November 10, 2020, with changes adopted April 12, 2022 and January 23, 2024 [7].
None of the three published ADU chapters, in codes updated through May or June 2026, shows a change after 2024 [5][6][7].
We found no published reply from Los Altos or Saratoga. In an earlier letter, dated May 28, 2025 in HCD's letters dashboard (its own date line reads May 28, 2026), HCD wrote that it had been informed Mountain View intended to use state ADU law until the end of 2026, when it hoped to adopt a new ordinance. HCD said that doesn't satisfy Government Code §66326(b); to use state law instead, the city should repeal the old ordinance [8]. Menlo Park got the same December letter [9] and adopted a new ADU ordinance on June 9, 2026 [10]; see our note on Menlo Park.
Amiari Construction builds ADUs and additions on the Peninsula.
How we checked this: In October 2026, Amiari Construction read HCD's letters to the four cities, the three cities' published ADU codes, Menlo Park's June 29 announcement and Government Code §66333.
