347 Jean St
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.87834, -122.53148
Executive Verdict · Public-Records Synthesis
Zoned R1 in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AH flood / CAL FIRE moderate fire hazard severity zone (local responsibility area) due diligence; benchmark value $2,114,000 ($1,860,000–$2,368,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone R1 allows residential use qualifying for ministerial ADU review under state law (11 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$13,860 contributory est.)
Public building records show issued construction/renovation work on this parcel (3 total permits, latest Oct 2, 2023).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Tamalpais
50 substantial renovation & housing permits over 24 months (20.5 per 1,000 parcels vs. 16.4 citywide baseline) (#3 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Tamalpais)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (AH, about 1% of the lot of lot)
Zone AH: 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)
- ! CAL FIRE Moderate Fire Hazard Severity Zone (Local Responsibility Area) (about 94% of the lot of lot)
Located in a mapped Fire Hazard Severity Zone. Expect Chapter 7A ignition-resistant building standards, defensible-space inspections, and stricter property insurance underwriting.
Source: CAL FIRE FHSZ (map Mar 24, 2025)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 403 Marin Ave (adu 403a) (0.23 mi W, 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 (~$24,761/yr at $2,114,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,063/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:
- 7,275 sq ft (0.17 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 347 JEAN ST
Zoning & Land Use
R1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned R1, a single-family residential zone. FEMA Special Flood Hazard Area (Zone AH) covers about 1% 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 R1, a single-family residential zone. The lot is 7,275 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 AH) covers about 1% 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
- Moderate Fire Hazard Severity Zone (Local Responsibility Area) (about 94% of the lot, map Mar 24, 2025)
- FEMA National Flood Hazard Layer
- Zone AH: 1% annual chance flood (Special Flood Hazard Area) (about 1% of the lot); Zone X: 0.2% annual chance flood hazard (shaded X) (about 99% of the lot) · FIRM panel 06041C0468F, 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: $1,860,000 – $2,368,000 · Status: Off market
HUD Small Area FMR (ZIP 94941) · FY 2026
Studio $2,730 · 1BR $3,270 · 2BR $3,960 · 3BR $5,060 · 4BR $5,240
Developments Deserving Closer Investigation & Active Area Builders
- Accessory dwelling unit at 403 Marin Ave (adu 403a) (Issued)0.23 mi W
Active in "Issued" for 2.9 yr (first record Dec 21, 2023) with no new permit activity recorded in 19 mo. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
- New home at 469 W Live Oak Dr (aka 461) (Issued)0.48 mi W
Active in "Issued" for 6.1 yr (first record Oct 22, 2020) with no new permit activity recorded in 22 mo. High-impact scale (1 housing unit, $980,000 declared valuation across 1 permit).
- New home at 217 Cleveland Ave (Issued)0.5 mi N
Active in "Issued" for 9.7 yr (first record Feb 21, 2017) with no new permit activity recorded in 2.3 yr. High-impact scale (1 housing unit, $875,000 declared valuation across 1 permit).
- Accessory dwelling unit at 384 Woodside Ave (Applied)0.22 mi NW
In "Applied" for 2 yr (since Oct 25, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Entity-resolved builders & contractors in ½ mile: Sonoma Power Solutions (1 on parcel, 1 in ½ mi · Solar / battery storage); Golden Gate Home Improvement (1 on parcel, 1 in ½ mi · Windows / doors / siding); Able Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Owner Builder (87 in ½ mi · Remodel / interior alteration); Owner (50 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (3 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B35609 | Solar / battery storage | Issued | Iss. Oct 2, 2023 | $35,000 | Rooftop Solar and energy storage for partial home backup power. |
| B30246 | Windows / doors / siding | Issued | Iss. Jun 30, 2022 | $17,720 | Replace (4) windows, same size as existing. — Non-structural Door/Window Replacement |
| B28633 | Roof replacement | Issued | Iss. Feb 6, 2022 | $16,185 | REMOVE AND REPLACE CLASS A COMP SHINGLE ROOF. — ReRoofing; With Electronic Inspection |