ADU Laws · 2026
Monterey County ADU Regulations (2026)
In Monterey County, ADU regulations are governed first by California state law, which preempts local rules. That means you can build a detached ADU up to 1,200 sq ft, with setbacks of no more than 4 feet on the sides and rear, and your city must approve or deny a complete application within 60 days with no public hearing. Local details like exact fees and design standards vary by city (Salinas, Marina, Monterey, Pacific Grove, Carmel), but they cannot override the protections the state guarantees you.
The short version: California state law sets the floor for every city in Monterey County. You get up to 1,200 sq ft detached, 4-foot setbacks, ministerial (no-hearing) approval, no owner-occupancy requirement, and a 60-day decision clock. City-specific fees and design rules layer on top, and we confirm those for your exact address in the feasibility study.
State law is the baseline everywhere in Monterey County
The most important thing to understand about ADU rules in Monterey County is that the strongest protections come from Sacramento, not city hall. California has spent years rewriting its ADU laws to make these projects fast and predictable, and those laws apply to Salinas, Marina, Monterey, Pacific Grove, Carmel, and the unincorporated county alike.
Here is the statewide baseline that no local ordinance can take away from you:
| Rule | What state law guarantees |
|---|---|
| Detached ADU size | Up to 1,200 sq ft of new construction |
| Minimum guaranteed | Cities must allow at least 800 sq ft / 16 ft height, whatever local rules say |
| Side & rear setbacks | 4 feet maximum required (less for conversions) |
| Approval type | Ministerial (no public hearing, no discretionary review) |
| Decision deadline | City must approve or deny a complete application in 60 days |
| Owner-occupancy | Not required for an ADU (suspended by the state) |
| Parking | At most 1 space, with broad exemptions (see below) |
| Impact fees | Waived for ADUs under 750 sq ft |
| Units allowed | A single-family lot can generally have the home + 1 ADU + 1 JADU |
Because state law preempts conflicting local rules, a straightforward detached ADU on a normal Monterey County lot is a by-right project, not a negotiation with the planning department.
Setbacks, height, and where the ADU can go
State law caps the required side and rear setback at 4 feet. Your city cannot demand 10 or 15 feet for a new detached ADU. If you are converting space inside an existing structure (like a garage conversion), no additional setback is required within that existing footprint. The front setback generally follows whatever applies to your primary residence.
Height is protected too: every city must allow at least a 16-foot ADU, and taller limits often apply near transit. On the Monterey Peninsula, coastal and historic-district overlays can add design review on top of the state baseline, which is exactly the kind of local wrinkle we flag early. See whether your specific lot qualifies.
Parking: usually not required
Parking is where a lot of Monterey County homeowners get tripped up by old assumptions. State law limits ADU parking to at most one space, and then exempts you from even that in most real-world situations:
- Within 1/2 mile walking distance of public transit
- Within an architecturally or historically significant district
- When the ADU is part of the primary home or an existing structure
- In an area that requires on-street parking permits
- Within one block of a car-share vehicle
- When the ADU replaces a garage or covered parking (no replacement spaces required)
In the walkable parts of Salinas, Monterey, and Pacific Grove, the transit exemption alone takes parking off the table for a large share of lots. We confirm which exemption applies to your address in the feasibility study so it never becomes a surprise.
ADU vs. JADU in Monterey County
You can often have both an ADU and a Junior ADU on the same single-family lot. They follow different rules:
| Feature | ADU | JADU |
|---|---|---|
| Max size | Up to 1,200 sq ft (detached) | Up to 500 sq ft |
| Where it’s built | Detached, attached, or a conversion | Inside the walls of the existing home |
| Owner-occupancy | Not required | Required |
| Kitchen | Full kitchen | Efficiency kitchen; bathroom may be shared |
A common Monterey County setup is a detached factory-built ADU in the backyard plus a JADU carved out of the main house. For a full breakdown, read JADU vs. ADU.
What actually varies by city
State law sets the floor, but each Monterey County city handles the local layer differently. These items genuinely vary, and they are exactly what your free feasibility study confirms for your address:
- Permit and plan-check fees. These vary by city and are not posted as one flat number.
- Impact and connection fees. Waived under 750 sq ft, charged proportionally above that, with amounts set locally.
- Design and overlay standards. Carmel, Pacific Grove, and coastal-zone properties often carry extra design review.
- Utility connections. Sewer vs. septic and water-meter requirements differ across the county.
We never quote these from memory. Local fees and specifics are confirmed in the feasibility study so your number is real, not a guess.
How Framework First fits the local picture
Our factory sits in Salinas, right in the heart of Monterey County, so the cities in our backyard are the ones we know best. We have run plan check across the Monterey Bay many times, which means we draft plans the way local departments want to see them, keeping you in the single-round lane instead of months of resubmittals.
Every Framework First ADU price includes a permitting budget alongside plans, foundation, the factory build, delivery, hookups, appliances, and final inspection. Permit costs themselves are set by your city or the county, so they’re confirmed for your specific parcel in the feasibility study rather than quoted from a general list. Our pricing runs $180,000 to $557,000, across 14 models from 405 to 1,200 sq ft, delivered in 4 to 9 months, and built roughly 97% in our factory before being crane-delivered to your lot. We are family-owned and have been since 2021 (CSLB #1047146, MFG #1595931).
If you want to see what fits, browse our models and transparent pricing, or run the numbers yourself with the ADU calculator. When you are ready for the city-level detail, the feasibility study ties it all to your address.
We build across Monterey County and beyond. Start with your city: Salinas, Marina, or Monterey.
Frequently asked questions
Do I need owner-occupancy to build an ADU in Monterey County?
No. California has suspended the owner-occupancy requirement for ADUs, and that applies throughout Monterey County. You can build an ADU and rent out both the main house and the ADU. Owner-occupancy is still required for a JADU (Junior ADU), so if you plan that smaller unit inside your existing home, you or a family member must live on the property. See our California ADU rental laws guide for the renting picture.
How big can my ADU be?
A detached, new-construction ADU can be up to 1,200 sq ft under state law, and your city must allow at least an 800 sq ft unit regardless of local zoning. Our models range from 405 to 1,200 sq ft, so there is a fit for compact backyards and larger lots alike. Browse the full model catalog to compare layouts.
How long does ADU approval take here?
Once you submit a complete application, the city has 60 days to approve or deny it, by state law. Approval is ministerial, meaning there is no public hearing or neighbor sign-off. Because we build your unit in the factory while permitting and the foundation move in parallel, total delivery runs 4 to 9 months. See the full ADU permit timeline.
Will an HOA or coastal rules stop me?
HOAs cannot unreasonably prohibit ADUs in California, so an HOA is rarely a hard stop. Coastal-zone and historic-district properties (common on the Monterey Peninsula) can carry extra design review, but that is a layer on top of your state-law rights, not a veto. We identify any overlay that applies to your lot in the feasibility study before you commit.
Are fire sprinklers required for my ADU?
Only if your primary residence is already required to have them. State law says an ADU does not trigger a new sprinkler requirement on its own. Like all local specifics, we confirm the exact requirement for your address as part of the process.
Curious what the rules mean for your backyard? Get a feasibility study and we will confirm exactly what state law guarantees you, what your city requires, and what is possible on your lot, all tied to your specific Monterey County address.