42 Main St
San Quentin 94964 · San Quentin · Unincorporated Marin · Coordinates: 37.94118, -122.48385
Executive Verdict · Public-Records Synthesis
Zoned RSP-5.8-BFC in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA VE flood due diligence; benchmark value $1,415,000 ($1,203,000–$1,627,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RSP-5.8-BFC allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$44,000 contributory est.)
Public building records show issued construction/renovation work on this parcel (3 total permits, latest Sep 30, 2026).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (VE, about 17% of the lot of lot)
Zone VE: 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)
- ! 1 slow or stalled nearby project within ½ mile
Closest lead: New home at 22 Mckenzie St (290 ft N, issued). 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 (~$16,723/yr at $1,415,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,394/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:
- 5,314 sq ft (0.12 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 42 MAIN ST
Zoning & Land Use
RSP-5.8-BFC — Residential Single Family Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RSP-5.8-BFC (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned RSP-5.8-BFC, a single-family residential zone. FEMA Special Flood Hazard Area (Zone VE) covers about 17% 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-BFC, a single-family residential zone. The lot is 5,314 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 VE) covers about 17% 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 VE: 1% annual chance flood (Special Flood Hazard Area) (about 17% of the lot); Zone X: minimal flood hazard (about 83% of the lot) · FIRM panel 06041C0478E, 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: $1,203,000 – $1,627,000 · Status: Off market
HUD Small Area FMR (ZIP 94964) · FY 2026
Studio $2,530 · 1BR $3,040 · 2BR $3,680 · 3BR $4,700 · 4BR $4,870
Nearby Activity (½ mile radius, since November 2024)
0 active or recent development projects and 12 total building permits recorded within ½ mile.
- Additions & renovations2 permits
- Building systems8 permits
Developments Deserving Closer Investigation & Active Area Builders
- New home at 22 Mckenzie St (Issued)290 ft N
Active in "Issued" for 3.9 yr (first record Dec 27, 2022) with no new permit activity recorded in 2.8 yr. High-impact scale (1 housing unit, $850,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Owner (1 on parcel, 2 in ½ mi · Other); Mark Scott Construction (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Safe And Warm Chimney Service (1 on parcel, 1 in ½ mi · HVAC / heat pump); James Flanagan Builder (2 in ½ mi · New garage / accessory structure); Rodd Renovations (1 in ½ mi · New single-family home).
Permit & Project History on This Parcel (3 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 182643 | Remodel / interior alteration | Issued | Iss. Sep 30, 2026 | $80,000 | Water Damage Repair Limited To Lower Level. Like-For-Like Restoration. Construct (N) Retaining Wall Under Entry Deck. |
| 144621 | Other | Issued | Iss. Oct 23, 2014 | $400 | Fireplace Enclosure For Permit # 144549 |
| 144549 | HVAC / heat pump | Issued | Iss. Oct 15, 2014 | $1,769 | Repl & Relocate Gas Burning Firepl. Firepl Enclosure To Be Permitted By Owner |