ADU Laws · 2026
San Benito County ADU Regulations (2026)
In San Benito County, you can build a detached accessory dwelling unit (ADU) of up to 1,200 square feet on most single-family lots, and the county and its cities must approve a complete application within 60 days with no public hearing. California’s statewide ADU law sets that floor, and it overrides any stricter local rule, so whether you’re in unincorporated county land, Hollister, or San Juan Bautista, the same generous baseline protects your project.
The wrinkle in San Benito County is a happy one: lots here tend to be larger than in the dense Bay Area cities to the north. More land usually means easier placement, fewer setback headaches, and room for a full-size ADU without crowding the primary home.
The short version: State law lets you build an ADU up to 1,200 sq ft in San Benito County, with 4-foot side and rear setbacks, ministerial (no-hearing) approval, and a 60-day decision deadline. Local fees and a few details vary by jurisdiction, and we confirm those for your exact address in a feasibility study.
State law sets the floor (and it’s generous)
The most important thing to understand about San Benito County ADU regulations is that they sit on top of California state law, and state law wins. Cities and counties can add reasonable local detail, but they cannot drop below the statewide minimums. Here’s what that guarantees you anywhere in the county:
- Size: A detached, new-construction ADU is allowed up to 1,200 sq ft. Even where local rules try to limit you, the county must allow at least an 800 sq ft ADU at 16 feet of height.
- Setbacks: A maximum of 4 feet is required on the side and rear. Conversions inside an existing structure’s footprint need no added setback. The front setback generally matches your primary residence.
- Ministerial approval: Your ADU is reviewed over-the-counter style. No public hearing, no discretionary review, no neighbor sign-off.
- 60-day clock: Once your application is complete, the jurisdiction has 60 days to approve or deny it.
- No owner-occupancy requirement: You do not have to live on the property to build or rent an ADU. (A junior ADU is the exception, see below.)
- Parking relief: At most one parking space is required, and broad exemptions often eliminate even that.
If you’ve read horror stories about ADU permitting, they’re almost always from the old rules. The modern framework is designed to make a standard detached ADU a by-right project.
Why San Benito County’s larger lots help
Much of San Benito County, including the unincorporated areas around Hollister and the rural stretches toward Tres Pinos and Paicines, features lots that are simply bigger than a typical quarter-acre Silicon Valley parcel. That matters for three practical reasons:
- Placement is easier. With a 4-foot minimum side and rear setback under state law, a roomy lot gives you many valid spots for the unit, including positions that keep it out of sight of the street or close to a separate driveway for a rental.
- You can go full size. Squeezing a 1,200 sq ft ADU onto a tight urban lot can run into lot-coverage limits. On a larger San Benito parcel, the full size is usually no problem.
- Septic and well, not always sewer. Some rural properties run on septic and well water rather than city sewer. That’s workable, but it’s one of the specifics worth confirming early, because it can affect placement and hookups. We check this in the feasibility study so there are no surprises.
Hollister and San Juan Bautista
Most of the county’s homeowners live in or near Hollister, the county seat, or the historic town of San Juan Bautista. Both are incorporated cities, so they administer their own ADU permits, but both are bound by the same state baseline above.
San Juan Bautista has historic-district considerations in parts of town, which can affect exterior design and review for some addresses. That doesn’t block an ADU, but it’s a detail worth flagging up front. In Hollister, ADUs on standard residential lots are a well-trodden, by-right path.
| Jurisdiction | Who reviews the permit | Notable local factor |
|---|---|---|
| Unincorporated San Benito County | County planning | Larger lots; some septic/well parcels |
| Hollister | City of Hollister | Standard residential ADU path |
| San Juan Bautista | City of San Juan Bautista | Historic-district design review in parts of town |
Exact permit fees, school-impact considerations, and processing nuances differ by jurisdiction. We don’t quote a generic number, because it would be wrong for your specific lot. Your feasibility study itemizes the real, address-specific picture.
Setbacks, parking, and how many units you can have
Setbacks
State law caps the required side and rear setback at 4 feet. A larger San Benito lot rarely makes this a constraint. If you convert space inside an existing structure (say, a detached garage or a barn footprint), no additional setback is required at all.
Parking
You’ll often owe zero added parking. State exemptions apply when the ADU is within a half-mile walking distance of public transit, sits within an existing structure, is in an on-street permit area, is within one block of car-share, or replaces a garage or covered parking (no replacement parking required in that case). For many Hollister addresses near transit, this clears the parking question entirely.
How many units
A single-family lot in California may generally have the primary home + one ADU + one JADU. So on a typical San Benito County single-family parcel, you can add an ADU now and still have room for a junior ADU later. Multifamily and larger properties can support more.
Impact fees and the 750 sq ft line
Impact fees are waived entirely for ADUs under 750 square feet. For a larger ADU, fees are charged proportionally to size rather than as a flat charge. This is one reason many homeowners weigh the tradeoff between a sub-750 footprint (lower fees, often plenty of room for a one-bedroom rental or in-law unit) and a full 1,200 sq ft build. Our models range from 405 to 1,200 sq ft, which gives you options on either side of that line.
What Framework First handles for you
We’re a family-owned builder based in Salinas, about a half-hour from Hollister, and San Benito County is squarely inside our service area. We build roughly 97% of each home in our own factory and crane-deliver it to your lot. The price you see includes a permitting budget along with plans, foundation, the factory build, delivery, hookups, appliances, and the final inspection, all rolled into one number that runs $180,000 to $557,000 depending on the model and finishes. Your actual permit costs are set by the county or city, so they’re specific to your parcel and get confirmed during the feasibility study.
Because the unit is being built in the factory while your permit and foundation move forward, the whole project lands in 4 to 9 months rather than the year-plus a typical site build takes. Our team manages the county or city paperwork on your behalf, handling the back-and-forth with the planner so you’re not the one tracking down submittals or inspections. See how the process works for the step-by-step.
Frequently asked questions
How big of an ADU can I build in San Benito County?
Up to 1,200 square feet for a detached new-construction ADU under California state law, and the county must allow at least 800 sq ft at 16 feet tall regardless of local rules. San Benito’s larger lots usually make the full size easy to fit. Use our cost calculator to see what different sizes look like.
Do I need a public hearing to build an ADU in Hollister or San Juan Bautista?
No. ADU approval is ministerial statewide, which means there’s no public hearing and no discretionary review. The jurisdiction checks your complete application against the rules and must approve or deny within 60 days.
Do I have to live on the property to build an ADU?
No. California has suspended the owner-occupancy requirement for ADUs, so you can build and rent one even if you don’t live on-site. The one exception is a junior ADU (JADU), which is up to 500 sq ft, created within the walls of an existing home, and does still require owner-occupancy. See our JADU vs ADU guide for the difference.
What about properties on septic and well instead of city sewer?
Many rural San Benito parcels are workable on septic and well. It’s just a detail we confirm early, since it can influence where the unit sits and how hookups are handled. The feasibility study checks this for your specific address before you commit to anything.
Will an ADU raise my property taxes a lot?
You’re reassessed only on the added value of the ADU, not your whole property, and your existing home keeps its current (often lower) assessed value. We cover this in depth in our ADU property tax guide.
Want to know exactly what’s possible on your San Benito County lot, including the real local fees, setback fit, and timeline for your address? Get your feasibility study and our team will map out the by-right path for your property. You can also explore nearby Salinas and the wider Monterey area if you’re weighing options across the region.