105 Montego Key
Novato 94949 · Bel Marin Keys · Unincorporated Marin · Coordinates: 38.08592, -122.52635
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 $1,416,000 ($1,246,000–$1,586,000).
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 (+$17,920 contributory est.)
Public building records show issued construction/renovation work on this parcel (6 total permits, latest May 19, 2026).
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)
- ! Year 1 Prop 13 tax reset (~$16,734/yr at $1,416,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,395/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:
- 15,420 sq ft (0.35 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 105 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 15,420 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: $1,246,000 – $1,586,000 · 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
Entity-resolved builders & contractors in ½ mile: Semper Solaris (2 on parcel, 2 in ½ mi · Solar / battery storage); Baths For Less (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Semper Solaris Construction (1 on parcel, 1 in ½ mi · Solar / battery storage); Ernest Ongaro And Sons (1 on parcel, 1 in ½ mi · HVAC / heat pump); Gagne Brothers Enterprises (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer).
Permit & Project History on This Parcel (6 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B46851 | Plumbing / water heater / sewer | Issued | Iss. May 19, 2026 | $9,000 | Replace Plumbing Fixtures(s) |
| B32995 | HVAC / heat pump | Issued | Iss. Mar 15, 2023 | $5,400 | Replace failed furnace with new furnace — Replace Mechanical Appliance |
| B29441 | Plumbing / water heater / sewer | Issued | Iss. Apr 18, 2022 | $4,500 | REPLACING 50 GALLON GAS WATER HEATER. — Replace Plumbing Fixtures(s) |
| B27045 | Solar / battery storage | Issued | Iss. Sep 17, 2021 | $8,490 | Installing (N) 3 kW (AC), (DC) 2.16 kW PHOTOVOLTAIC SYSTEM ROOF MOUNTED, to an (E) ROOF MOUNTED PHOTOVOLYAIC SYSTEM ALRE… |
| 162927 | Solar / battery storage | Issued |