ADU Laws · 2026
Building an ADU in the Monterey County Coastal Zone
If your Monterey County property sits within the Coastal Zone, common along the Monterey Peninsula and much of the coastline, a Coastal Administrative Permit is required in addition to your standard ADU permit. This is an added review layer, not a replacement for your state-law rights. You still get the same size, setback, and timeline protections every California homeowner gets; the coastal layer is about additional design and environmental review specific to that zone.
The short version: Coastal Zone parcels need a Coastal Administrative Permit alongside the normal ADU permit. It adds a review step, not a veto. Your state ADU protections (up to 1,200 sq ft, 4 ft setbacks, ministerial approval) still apply underneath it. We identify this immediately during your feasibility study.
What triggers the Coastal Zone requirement
California’s Coastal Zone is a mapped area along the coastline, and whether your specific parcel falls inside it depends on its exact location relative to that boundary, not just “is my property near the ocean.” Properties along the Monterey Peninsula, and various parcels elsewhere in the county close to the coastline, can fall inside this mapped area. The only reliable way to know is to check your specific parcel, which we do as part of the feasibility study.
What a Coastal Administrative Permit actually adds
The Coastal Administrative Permit is a separate approval, on top of your ADU building permit, focused on coastal-specific concerns like:
- Visual and design review consistent with the Local Coastal Program
- Environmentally sensitive habitat considerations, where applicable
- Public access and viewshed protections in some areas
It does not remove any of the protections state ADU law guarantees you. You still get:
| Right | Still applies in the Coastal Zone |
|---|---|
| Up to 1,200 sq ft detached ADU | Yes |
| Maximum 4 ft side/rear setback | Yes |
| Ministerial approval (no discretionary hearing on the ADU itself) | Yes, for the ADU permit; the coastal permit is a separate process |
| 60-day decision clock (ADU permit) | Yes |
Septic and utility considerations near the coast
Coastal Zone parcels in Monterey County are also more likely to be on septic systems rather than a sewer connection. As with any septic lot, if your parcel is under roughly 1.25 acres, adding an ADU usually requires an upgraded, alternative septic system. This isn’t unique to the Coastal Zone, but it comes up often enough on coastal parcels that we check it early, alongside the coastal permit question, during the feasibility study.
What this means for your timeline
The Coastal Administrative Permit adds a review step, which means coastal parcels generally take longer to permit than an equivalent inland lot. It does not change your underlying entitlement to build an ADU. See our Monterey County permit timeline guide for how the standard 60-day clock works, and understand that a coastal review layers on top of it rather than replacing it.
How Framework First handles Coastal Zone properties
We flag Coastal Zone status immediately when we pull your property records, before you spend time or money moving forward. If your parcel qualifies, we build the coastal review into your feasibility study and timeline expectations from day one rather than surprising you with it mid-project.
Every Framework First ADU price includes a permitting budget alongside plans, foundation, the factory build, delivery, utility hookups, appliances, and final inspection, running $180,000 to $557,000 across 14 models from 405 to 1,200 sq ft, delivered in 4 to 9 months. Actual permit and coastal review costs are set by the county, so they’re confirmed for your specific parcel in the feasibility study. We’re family-owned, based in Salinas since January 2021 (CSLB #1047146, MFG #1595931), and have built across the Monterey Peninsula’s coastal communities.
See models that fit smaller coastal lots, or start with your city: Monterey, Marina, or Salinas.
Frequently asked questions
How do I know if my property is in the Coastal Zone?
The Coastal Zone follows a specific mapped boundary, not a general “near the ocean” rule. We check your exact parcel against that boundary as part of the feasibility study, so you get a definitive answer rather than a guess.
Does the Coastal Zone requirement mean my ADU could be denied?
No. The Coastal Administrative Permit is a design and environmental review layer, not a veto over your right to build an ADU under state law. It can add conditions or take longer to review, but your underlying entitlement to a state-law-compliant ADU remains intact.
Will a coastal permit make my project more expensive?
It can add fees and time associated with the additional review, though the underlying ADU fee structure (including the under-750 sq ft impact fee waiver) is unaffected. See our Monterey County fees guide for the fee picture generally.
Does living on septic near the coast complicate things further?
It can, if your lot is under about 1.25 acres and needs an upgraded septic system to support an ADU. We check septic capacity alongside coastal status early in the process so both are accounted for before you commit.
Not sure if your property falls in the Coastal Zone? Start a feasibility study and we’ll confirm exactly what applies to your specific Monterey County parcel.