Pre-Approved ADU Plans in Ventura County (2026 Guide)

Say you're pricing a detached ADU in Camarillo, and a neighbor mentions their city has "free pre-approved plans" that skip the architect fee entirely. That's half true, and the half that's missing is the expensive half.

Assembly Bill 1332 required every city and county in California to stand up a pre-approved ADU plan program by January 1, 2025. That deadline is well behind us now, and the results across Ventura County are uneven. Four jurisdictions have a working program we could verify directly on their own government websites. Two more have plans published but not fully finalized. Three have a dedicated ADU page that plainly doesn't mention a pre-approved plan program, which we confirmed by reading that page directly rather than assuming. Two we genuinely couldn't confirm either way, because the city's own website blocked every attempt to load it. We checked all eleven Ventura County jurisdictions, city by city, against their own .gov pages rather than against what a builder's blog claims about them. This guide reports exactly what we found, plus the plain accounting that most "free pre-approved plans" marketing leaves out: the specific list of costs a pre-approved plan never touches.

We're a licensed general contractor, CA Lic. #1066117, 20+ years building ADUs across Ventura County, 5.0 stars on Google. Call us at (805) 222-6544 or start at SafewayRemodel.com, and we'll tell you plainly whether a pre-approved plan fits your lot, or whether you're better off going custom from the start.

Quick Answer

Government Code Section 65852.27, added by AB 1332, required every California city and county to develop a pre-approved ADU plan program by January 1, 2025. In Ventura County, we could directly verify a working program on four jurisdictions' own websites: the City of Ventura and unincorporated Ventura County each offer three free layouts (700, 900, and 1,188 square feet), already reviewed by their Building and Safety divisions; Ojai offers a free ~500 square foot one-bedroom plan in three architectural styles; and Thousand Oaks runs a designer-submittal model, where outside designers submit plans for the city to preapprove, rather than a fixed city-drawn catalog. Moorpark and Santa Paula have plan sets published, but Moorpark's own page frames them as structural templates only, and Santa Paula's six standard plans are explicitly labeled "draft only" pending finalization. Camarillo, Fillmore, and Port Hueneme each have a dedicated ADU page that we read directly and that does not mention a pre-approved plan program. Simi Valley and Oxnard remain genuinely unverified, because both cities' websites blocked every direct load attempt. Call each city's planning counter directly (numbers below) before assuming any status either way.

And regardless of which city you're in: a pre-approved plan never pays for your soils report, your site-specific engineering, your Title 24 energy compliance, your utility connections, your impact fees, or your site plan. Those get priced and reviewed on every ADU project, pre-approved shell or not.

Want a real number for your Ventura County ADU before you commit to a plan set? Call (805) 222-6544 for a free estimate, no site visit required to start the conversation.

What We Actually Found, City by City

None of the phone numbers in the table below are ours. Each one is a direct line to that city's own planning or building department, included so you can call and verify current status yourself.

|---|---|---|---|

| City of Ventura | Working program | Three free layouts: 700 sf (1BR), 900 sf (2BR), 1,188 sf (3BR). Already reviewed by Building & Safety. City states applicants get reduced review fees and reduced review time versus a custom design. | Verified primary, cityofventura.ca.gov |

| Unincorporated Ventura County (RMA) | Working program | Same three-layout structure (700/900/1,188 sf), free of charge, described by the county as "already reviewed and pre-approved by the Building and Safety Division." | Verified primary, rma.venturacounty.gov |

| Ojai | Working program | A free pre-approved one-bedroom plan, roughly 500 sf, listed directly on the Planning & Zoning Division page as "ADU Pre Approved Plans (PDF)," offered in three architectural styles: Ranch, Spanish, and Traditional. | Verified primary, ojai.ca.gov/246/Planning-Zoning-Division |

| Thousand Oaks | Working program, designer-submittal model | Runs an "ADU Plans Gallery" through a third-party portal where outside designers submit plans for the city to preapprove, rather than a fixed set the city drew itself. A homeowner still submits a site-specific plan against a chosen preapproved design. | Verified primary, toaks.gov/index.php?section=adu |

| Moorpark | Partial / structural only | Three Standard Plans in the same sizes (700/900/1,188 sf) exist, but the city's own page describes them as covering structural design only, "rough floor plans," still requiring separate Ventura County Fire, water/sanitary district, and school district sign-off plus a full site plan and Title 24 forms. | Verified primary, plans exist; AB 1332 fee/time-reduction status not confirmed on the page |

| Santa Paula | In progress | Six named standard plans listed (ADU A350, A400, A400R, AG436, A640, A750), but the page states plainly: "ALL PLANS ARE DRAFT ONLY AT THIS TIME. CONTACT THE BUILDING & SAFETY DIVISION FOR FURTHER DETAILS." | Verified primary, spcity.org; not yet approved for use |

| Camarillo | No program found | The city's dedicated ADU page, read directly, contains zero mentions of "pre-approved" or standardized plans, only general design-cost guidance and its Zone Clearance review process. | Verified primary (no mention found), cityofcamarillo.org; call (805) 388-5340 |

| Fillmore | No program found | The city's own ADU page, read directly, does not mention a pre-approved plan program. | Verified primary (no mention found), fillmoreca.gov; call (805) 946-1862 ext. 114 |

| Port Hueneme | No program found | The city's own ADU submittal checklist and Planning & Zoning page, read directly, do not mention a pre-approved plan program. | Verified primary (no mention found), ci.port-hueneme.ca.us; call (805) 986-6500 |

| Simi Valley | Unverified | The city's planning pages returned an access-denied response on every direct load attempt, by us and independently. No pre-approved plan program surfaced elsewhere on the city's own site. | Not primary-verified, site blocked; call (805) 583-6769 |

| Oxnard | Unverified | The city's ADU page blocked automated access on every attempt, by us and independently. We could not read the source content directly to confirm or deny a program. | Not primary-verified, site blocked; call (805) 385-7925 |

A page not mentioning a program isn't proof one doesn't exist informally at the counter, though for Camarillo, Fillmore, and Port Hueneme, we did read each city's own ADU page directly and found no mention of one. Simi Valley and Oxnard are a different case entirely: both cities' websites blocked every direct load attempt, so we genuinely don't know their status either way. Call before you assume anything either way, and if you get a different answer than what's here, that's useful information for us too, code pages change.

The Part Every "Free Pre-Approved Plans" Post Skips

Here's the split that matters, and it's the actual reason we built this guide instead of just listing plan sizes.

What a Pre-Approved Plan Saves You

Architectural design fees. A pre-approved plan is already drawn, structurally engineered for the base configuration, and reviewed once by the city. You're not paying an architect or designer to create it from scratch. Our ADU architectural design cost guide breaks down what a fully custom design typically runs in Ventura County; skipping that line item is the single biggest dollar savings a pre-approved plan offers.

Most structural plan review. Because the city's Building and Safety division already reviewed the structural design once, a project using an unmodified pre-approved plan generally moves through structural plan check faster than a custom submission, since the reviewer isn't checking framing calculations from zero.

Weeks of calendar time. This is the part with actual legal teeth behind it, and it's the single most concrete benefit in the entire statute. A standard ADU application in California gets a 60-day ministerial approve-or-deny clock under Government Code Section 66317(a)(3); miss that deadline and the application is deemed approved automatically. Government Code Section 65852.27(b) cuts that window in half for a pre-approved plan: a local agency must approve or deny within 30 days of a complete submittal, specifically when the application uses a plan the agency preapproved within the current triennial California Building Standards Code rulemaking cycle, or a plan identical to one it already approved in that same cycle. That's a hard statutory clock tied to using the plan as-is, half the length of what every other ADU applicant gets. A custom design doesn't get that same guarantee.

Trying to figure out if a pre-approved layout actually fits your lot's setbacks and square footage? Call <strong>(805) 222-6544</strong> and we'll walk through it before you commit to a plan set.

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What a Pre-Approved Plan Never Saves You

This is the list a lot of marketing quietly leaves out.

Site-specific engineering. A pre-approved plan is engineered for a generic flat pad. If your lot has a slope, expansive soil, or an unusual foundation condition, that plan needs a supplemental structural review specific to your site, at your cost.
Soils and geotech reports. Nothing about a pre-approved floor plan tells a plan checker what your soil can bear. Many Ventura County lots, especially hillside parcels around Ojai, Santa Paula, and unincorporated county land, still need a geotechnical report before foundation design gets finalized.
Title 24 energy compliance. California's energy code calculations are project-specific, tied to your unit's actual glazing, insulation, HVAC system, and orientation on your lot. A pre-approved shell doesn't include a pre-run Title 24 report for your address.
Utility connections, including any panel upgrade. Water, sewer, gas, and electrical laterals still have to be designed, permitted, and inspected for your specific parcel. If your existing electrical panel doesn't have capacity for a new detached unit, that panel upgrade is a separate cost no plan library touches.
Impact and connection fees. School, water, and other development impact fees are calculated per unit, per jurisdiction, and get charged regardless of which plan set you build from.
The permitting fees themselves, in most cases. This is the one homeowners assume incorrectly most often. Government Code Section 65852.27(a)(3)(B) explicitly permits a local agency to "charge the applicant the same permitting fees that the local agency would charge an applicant seeking approval" of a same-sized ADU through the normal process. Free plan, not automatically a cheaper permit. The fee waiver, where one exists, has to come from a separate local decision, not from the state law that created the plan program.
The site plan itself. A pre-approved floor plan tells the city what the structure looks like. It doesn't tell them where it sits on your lot. You still need a site plan showing your specific setbacks, lot coverage, and existing improvements, verified against your actual property lines, not a generic template.

Put plainly: a pre-approved plan replaces the architect's floor plan. It does not replace the surveyor, the soils engineer, the Title 24 consultant, the utility company, the permitting fee, or the site-specific plan check. Anyone pricing your ADU off "the plan is free, so the project is cheap" is skipping most of the line items above.

Why the Program Exists (and Why It's Uneven)

AB 1332 added Government Code Section 65852.27 to state law in 2023, with an operative deadline of January 1, 2025 for every local agency to have a program running. The statute is specific about what a compliant program has to do: accept plan submissions from anyone, not just city-approved vendors; approve or deny preapproval against the same standards used for any ADU application; post preapproved plans and the submitting applicant's contact information on the agency's own website; and remove a plan within 30 days if the original applicant requests it.

One detail explains some of what we found while researching this guide. The 30-day fast-track approval only applies to a plan preapproved "within the current triennial California Building Standards Code rulemaking cycle." California's building code updates on a roughly three-year cycle, and the current edition took effect January 1, 2026. That means plans a city preapproved under the prior code cycle may need to be re-reviewed and reissued to stay inside that fast-track window going forward. If a city's plan library looks thin or in flux right now, a code-cycle transition landing at the start of this year is a plausible part of why, not necessarily neglect.

The law also lets a local agency admit plans that were "preapproved by other agencies within the state" into its own program, under Section 65852.27(a)(5)(B). In practice that means a city without its own drawn set isn't necessarily starting from zero; it can adopt another jurisdiction's already-reviewed plans if it chooses to. Whether any specific Ventura County city has done that is exactly the kind of thing worth asking your local planning counter directly, since it isn't something that shows up consistently on a public-facing page.

If Your City's Page Doesn't Show a Program

A few honest options if you're sitting in one of the "unclear" rows above.

Call the counter and ask directly. State law required a program by January 1, 2025. If your city hasn't published one, that's worth a direct question, not an assumption either way. Some smaller departments run this informally, plan by request, without a dedicated web page.

Ask whether your city has adopted another agency's plans. Section 65852.27(a)(5)(B) specifically allows this. It's a fair, specific question to bring to a planning counter, and it's a faster ask than waiting on a city to draw its own set from scratch.

Treat a neighboring city's free plan as a design reference, not a usable set. A plan the City of Ventura preapproved isn't automatically valid in Camarillo or Fillmore unless that second city has formally admitted it. It can still be useful as a starting point for your own architect, showing a proven, buildable 700 or 900 square foot layout, even if it needs to be resubmitted under your city's own review.

Go custom from the start if your timeline can't wait on an unclear program. Our ADU cost calculator gives you a ballpark by size and finish level whether you're working from a pre-approved shell or a fully custom design, so you can compare both paths on the same numbers.

Call (805) 222-6544 and we'll price your ADU, pre-approved plan or custom design, and scope everything the floor plan doesn't cover, engineering, soils, Title 24, utilities, and your site plan, so you're comparing both paths on real numbers instead of guessing off a plan library that may or may not apply to your address. Your city's planning counter is still the right call for that program's current status.

Just Across the County Line: Agoura Hills and Westlake Village

Two more cities show up constantly in this conversation because they sit right on Ventura County's southern edge, and it's worth being precise about them: both are Los Angeles County, not Ventura County, and neither is included in our eleven-jurisdiction table above.

Agoura Hills has the most complete pre-approved catalog we came across anywhere in this search, Ventura County or not, three plan sizes (550 sf studio, 750 sf one-bedroom, and 1,000 sf two-bedroom), each available in three architectural styles and two foundation options, for up to 18 combinations, free, with building plan review fees waived. Planning review fees still apply, and a homeowner still needs a site-specific plan, same as everywhere else in this guide.

Westlake Village has a pre-approved plan program too, but it's narrower than it sounds: it covers garage conversions and Junior ADUs only, run through Los Angeles County's Building & Safety Division since Westlake Village's own building permits are issued by the county, not a city-specific department. That's a meaningfully smaller scope than a full detached-ADU catalog like Agoura Hills or the City of Ventura, worth knowing before you assume it covers a new standalone unit in your backyard.

If your project sits in either city, you're working with LA County's ADU rules and permitting process, not Ventura County's, even though both border Ventura County directly.

Comparing This to the Rest of the ADU Process

A pre-approved plan is one input into a larger project, not the whole project. If you're sizing up what an ADU costs overall in Ventura County, our ADU cost guide walks through construction pricing by size and finish level. If you're not sure how big a unit your lot can actually support, our ADU size limits guide covers the state floor and how local zoning interacts with it. And once you know your unit size and layout, setback and lot coverage rules determine where that plan can actually sit on your specific parcel, pre-approved or not.

If you're specifically in Simi Valley and trying to understand the full permit sequence beyond just the plan set, our Simi Valley ADU permit process guide walks through the three-agency path from application to final inspection.

The Bottom Line

Four Ventura County jurisdictions have a pre-approved ADU plan program we could verify directly on their own websites: the City of Ventura and unincorporated Ventura County both offer free 700, 900, and 1,188 square foot layouts; Ojai offers a free ~500 square foot plan in three styles; and Thousand Oaks runs a designer-submittal gallery model. Moorpark and Santa Paula have plans in some stage of development, not fully finalized as a fee-and-time-reduction program. Camarillo, Fillmore, and Port Hueneme each have a dedicated ADU page we read directly that simply doesn't mention a pre-approved plan program. Simi Valley and Oxnard remain genuinely unverified, both cities' sites blocked every direct load attempt. State law required all eleven to have a program by January 1, 2025, so a direct call to the counter is worth it either way.

And no matter which city you're in, remember what a pre-approved plan actually replaces: the architect's floor plan, and some of the structural review, on a faster 30-day statutory clock instead of the usual 60. It doesn't replace your soils report, your site-specific engineering, your Title 24 compliance, your utility connections, your impact fees, your permitting fees, or your site plan. Budget for all of that, whether your ADU starts from a free plan or a custom one.

Call (805) 222-6544 for a free estimate on the construction itself, pre-approved plan or custom design, or start at SafewayRemodel.com and we'll help you figure out which path actually fits your lot.

CA Lic. #1066117, 20+ years in business, 5.0 stars on Google, serving Simi Valley, Thousand Oaks, Moorpark, Camarillo, Oxnard, Ventura, Ojai, Santa Paula, Fillmore, Port Hueneme, and unincorporated Ventura County.

Frequently Asked Questions

What is AB 1332 and does it apply to my Ventura County city?

AB 1332 added Government Code Section 65852.27 to state law, requiring every California city and county, including charter cities, to develop a program for preapproving accessory dwelling unit plans by January 1, 2025. It applies statewide, so every jurisdiction covered in this guide was legally required to have a program running by that date, whether or not it's published clearly on their website today.

Which Ventura County city actually has a working pre-approved ADU plan right now?

Based on our direct check of each jurisdiction's own government website, four have confirmed, working programs: the City of Ventura and unincorporated Ventura County (through the county's Resource Management Agency) offer free 700, 900, and 1,188 square foot layouts already reviewed by Building and Safety; Ojai offers a free ~500 square foot plan in three architectural styles; and Thousand Oaks runs a designer-submittal gallery model. Moorpark and Santa Paula have plans published but not fully finalized as a fee-reduction program. Camarillo, Fillmore, and Port Hueneme each have a dedicated ADU page we read directly with no mention of a pre-approved plan program. Simi Valley and Oxnard remain unverified, both cities' websites blocked every direct load attempt.

Does using a pre-approved plan mean I skip the permit process?

No. You still have to submit a complete application, including a site-specific plan showing your setbacks and lot coverage, and the city still reviews and issues a permit. What changes is the structural design review, which is largely already done, and the statutory approval clock: a standard ADU application gets 60 days under Government Code Section 66317(a)(3), while a plan the city already preapproved gets a faster 30-day clock under Section 65852.27(b) when used unmodified.

What does a pre-approved ADU plan not include?

It does not include site-specific engineering, a soils or geotechnical report, Title 24 energy compliance calculations, utility connection design (including any electrical panel upgrade), impact or connection fees, or the site plan itself. It also doesn't automatically mean a cheaper permitting fee: Government Code Section 65852.27(a)(3)(B) specifically allows a local agency to charge the same permitting fees it would charge for any other ADU application of the same size. All of that gets priced and reviewed separately for every ADU project, regardless of which floor plan you start from.

Can I use one city's free pre-approved plan for a project in a different Ventura County city?

Not automatically. A plan the City of Ventura preapproved is valid there; it isn't valid in a different jurisdiction unless that city has formally admitted it into its own program under Government Code Section 65852.27(a)(5)(B), which allows a local agency to accept plans already preapproved by other California agencies. Ask your specific city's planning counter whether they've done this before assuming a neighboring city's plan will work for you.

How much does a pre-approved plan actually save compared to a custom design?

The main savings is the architectural design fee, which our ADU architectural design cost guide breaks down for Ventura County. Beyond that, savings come mostly from a faster structural plan-check and a shorter statutory approval clock rather than a large additional dollar figure, since soils work, Title 24, utility design, impact fees, and often the permitting fee itself cost roughly the same whether your floor plan came pre-approved or custom.

What if my city doesn't have a published pre-approved plan program yet?

Call the planning counter directly and ask. State law required a program by January 1, 2025, so it's a fair, direct question. Some smaller departments run an informal version without a dedicated web page. You can also ask whether the city has adopted another agency's already-approved plans, which state law specifically allows.

Do pre-approved ADU plans expire or need updating?

The statutory 30-day fast-track approval applies to plans preapproved within the "current triennial California Building Standards Code rulemaking cycle." California's building code updates roughly every three years, with the current edition effective January 1, 2026. A plan approved under a prior code cycle may need to be re-reviewed and reissued for a city to keep offering that same fast-track timeline going forward.

Do Agoura Hills or Westlake Village have pre-approved ADU plans?

Both do, but neither is in Ventura County, both are Los Angeles County. Agoura Hills has a full catalog: three sizes, three architectural styles, and two foundation options, free, with building plan review fees waived. Westlake Village's version, run through LA County Building & Safety, covers only garage-conversion ADUs and Junior ADUs, not a full detached-unit catalog. If your project is in either city, you're working under LA County's ADU process, not Ventura County's.

Pre-Approved ADU Plans in Ventura County: What Each City Actually Offers (2026)