A pre-approved plan is an ADU design a city has already reviewed and signed off. Build from one and you skip the slowest part of plan check — because the building itself has already been checked. 10 of the cities we build in run a program, and so does Santa Clara County.
30 days
to approve or deny a detached ADU built from a pre-approved plan
60 days
the ordinary statutory limit for everything else
Government Code § 65852.27, added by AB 1332. The plans have to be valid within the current triennial California Building Standards Code cycle.
01
The 30-day clock applies to a plan pre-approved by your local agency or any other agency in California — or even a plan identical to one in a detached-ADU application your city already approved. A design cleared in Gilroy can shorten a Sunnyvale permit.
02
Since 1 January 2025 local agencies have had to develop one, accept plan submissions for pre-approval from any party, and post the approved plans — plus the contact details of whoever submitted them — on their own website. Not every city has caught up.
03
This is the one that catches people out. Pre-approval clears the structure. Your site plan, setbacks, utility connections, grading and a foundation engineered for your soil are all still reviewed. Faster is not the same as skipped.
Links go to the jurisdiction's own page. Cities reorganise their sites constantly — if one has moved, the planning department page on our resources directory will get you there.
Publishes pre-approved plans already cleared by California HCD, plus a cost calculator. Plans still need a siting conversation with planning, but get a streamlined review.
Also runs a separate path for legalizing an existing unpermitted ADU.
Also runs an ADU Incentive Program and a Safe ADU legalization path for existing unpermitted units.
The deepest set of resources in the county — pre-approved plans, an ADU FAQ, a documented plan-review process, and a path for ADU condominium conversion under AB 1033.
Runs an Express Plan Check that can bring simple ADU approvals down from months to about a week. ADUs skip land-use entitlement and go straight to the Building Division.
The City Council approved a 50% reduction in building permit and plan check fees for a new ADU, including conversions of an existing pool house or garage.
Also publishes a path for legalizing unpermitted ADUs and JADUs.
Land outside any city's limits is permitted by the County, not a city — a distinction worth checking before you assume which rules apply. The County runs its own pre-approved plan program.
We haven't found a published pre-approved plan page for these — which is not the same as them not having one. State law has required a program since January 2025, cities publish them in different corners of their sites, and we've already found two that did run one after first concluding they didn't. Ask them.
Either way it may not matter: the 30-day rule accepts a plan pre-approved by any agency in California, so a design cleared elsewhere still counts.
We build from a city's pre-approved plan where one fits your lot, and we design from scratch where it doesn't. The choice is yours and it's not a close-run thing either way — it depends almost entirely on whether a catalogue footprint fits what your property can take once setbacks are drawn.
On the site walk we'll tell you whether your city's program has a plan that suits your lot, and what the trade is. Where it fits, it's usually the cheapest and fastest route you have.
The honest trade
A pre-approved plan is a fixed design. You gain review time and fees; you give up the freedom to shape the unit around an awkward lot, an existing structure, or a specific view. On a clean rectangular back yard that's a good deal. On a tight or sloped lot — which is a lot of what we build on — a custom footprint often wins the space back.
Our own six example plans are at floor plans. They're starting points, not a catalogue — the city's rules and your lot decide the final footprint.
That's two questions, and only the second one needs a site walk. We'll answer both — free, no obligation.
Tell us about your lot and what you're hoping to build. We'll follow up to schedule a feasibility walk — no obligation.
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