317 Montego Key
Novato 94949 · Bel Marin Keys · Unincorporated Marin · Coordinates: 38.08795, -122.51532
Executive Verdict · Public-Records Synthesis
Zoned RSP-5.8,F1-BFC in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AE flood due diligence; benchmark value $1,401,000 ($1,233,000–$1,569,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RSP-5.8,F1-BFC allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$24,960 contributory est.)
Public building records show issued construction/renovation work on this parcel (6 total permits, latest Jun 25, 2025).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (AE, all of the lot of lot)
Zone AE: 1% annual chance flood (Special Flood Hazard Area) overlaps this parcel. Expect mandatory flood insurance for federally backed loans and floodplain elevation/mitigation rules for new units or SB 9 applications.
Source: FEMA National Flood Hazard Layer (parcel polygon)
- ! 3 slow or stalled nearby projects within ½ mile
Closest lead: Demolition at 54 Calypso Shores (0.26 mi SE, applied). Inspect timeline history before assuming near-term completion.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · HCD APR (½-mile radius)
- ! Year 1 Prop 13 tax reset (~$16,562/yr at $1,401,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,380/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector
Parcel & Assessor
- Lot size:
- 12,502 sq ft (0.29 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 317 MONTEGO KEY
Zoning & Land Use
RSP-5.8,F1-BFC — Residential Single Family Planned (Unincorporated Marin)
Undesignated — Undesignated (Novato)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RSP-5.8,F1-BFC (single-family residential): state law allows ADUs where homes are allowed. The parcel point also falls in Undesignated.
- SB 9: two homes on the lotPossible, with conditions
Zoned RSP-5.8,F1-BFC, a single-family residential zone. The parcel point also falls in Undesignated. FEMA Special Flood Hazard Area (Zone AE) covers all of the lot: the project must meet the National Flood Insurance Program floodplain standards, or the lot needs a map revision.
- SB 9: split into two lotsPossible, with conditions
Zoned RSP-5.8,F1-BFC, a single-family residential zone. The parcel point also falls in Undesignated. The lot is 12,502 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original. FEMA Special Flood Hazard Area (Zone AE) covers all of the lot: the project must meet the National Flood Insurance Program floodplain standards, or the lot needs a map revision.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Not in a State-mapped fire hazard severity zone
- FEMA National Flood Hazard Layer
- Zone AE: 1% annual chance flood (Special Flood Hazard Area) (all of the lot) · FIRM panel 06041C0284E, effective March 16, 2016
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $1,233,000 – $1,569,000 · Status: Off market
HUD Small Area FMR (ZIP 94949) · FY 2026
Studio $2,360 · 1BR $2,830 · 2BR $3,430 · 3BR $4,380 · 4BR $4,540
Developments Deserving Closer Investigation & Active Area Builders
- Demolition at 54 Calypso Shores (Applied)0.26 mi SE
In "Applied" for 4.5 yr (since May 26, 2022), exceeding the 55d median and 261d 90th percentile for demolition permits in Unincorporated Marin (n=130).
- Demolition at 1051 Bel Marin Keys Blvd (Issued)0.4 mi S
Active in "Issued" for 8.5 yr (first record May 21, 2018) with no new permit activity recorded in 8.4 yr.
- Accessory dwelling unit at 1108 Bel Marin Keys Blvd (aka 1110) (Issued)0.46 mi SE
Active in "Issued" for 4.6 yr (first record Mar 23, 2022) with no new permit activity recorded in 4.4 yr.
Entity-resolved builders & contractors in ½ mile: Sunrun Installation Services (1 on parcel, 1 in ½ mi · Solar / battery storage); Adams Pool Solutions (1 on parcel, 1 in ½ mi · Electrical / panel); Contreras Heating And Air (1 on parcel, 1 in ½ mi · HVAC / heat pump); Tesla Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Elite Energy Electric (1 on parcel, 1 in ½ mi · Solar / battery storage).
Permit & Project History on This Parcel (6 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B42880 | Solar / battery storage | Issued | Iss. Jun 25, 2025 | $10,000 | Solar installation of 8.6kw system and 1 Franklin Apower2 Storage |
| B40700 | Solar / battery storage | Issued | Iss. Jan 2, 2025 | $40,513 | <p class=MsoNormal>Roof Mounted PV System, 6.72KW, 17 Modules, 1 ESS (desc updated 1.16.25)</p> |
| B31507 | Electrical / panel | Issued | Iss. Oct 24, 2022 | $3,000 | Upgrade main service panel from 100amp to 200amp. — Service Upgrade |
| B31077 | HVAC / heat pump | Issued | Iss. Sep 16, 2022 | $12,500 | Removing and replacing HVAC equipment — Replace Mechanical Appliance |
| 150243 | Solar / battery storage | Issued |