333 Ellen Dr
San Rafael 94903 · Marinwood · Unincorporated Marin · Coordinates: 38.02758, -122.55039
Executive Verdict · Public-Records Synthesis
Zoned RSP-1 in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AE flood due diligence; benchmark value $1,313,000 ($1,155,000–$1,471,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RSP-1 allows residential use qualifying for ministerial ADU review under state law (2 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$57,750 contributory est.)
Public building records show issued construction/renovation work on this parcel (2 total permits, latest Feb 11, 2022).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (AE, about 8% 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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home at 118 Erin Ct (0.25 mi E, 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 (~$15,550/yr at $1,313,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,296/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:
- 211,353 sq ft (4.85 ac)
- Assessor use:
- Exemption - Improved
- Addresses on lot:
- 333 ELLEN DR
Zoning & Land Use
RSP-1 — Residential Single Family Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RSP-1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned RSP-1, a single-family residential zone. FEMA Special Flood Hazard Area (Zone AE) covers about 8% 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-1, a single-family residential zone. The lot is 211,353 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 about 8% 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) (about 8% of the lot); Zone X: minimal flood hazard (about 92% of the lot) · FIRM panel 06041C0293E, 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: $1,155,000 – $1,471,000 · Status: Off market
HUD Small Area FMR (ZIP 94903) · FY 2026
Studio $2,880 · 1BR $3,450 · 2BR $4,180 · 3BR $5,340 · 4BR $5,530
Developments Deserving Closer Investigation & Active Area Builders
- New home at 118 Erin Ct (Applied)0.25 mi E
In "Applied" for 3 yr (since Nov 28, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $55,415,888 declared valuation across 1 permit).
- New home at 3 Erin Dr (Applied)0.25 mi E
In "Applied" for 3 yr (since Oct 31, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $2,993,758 declared valuation across 1 permit).
- New home at 111 Erin Ct (Applied)0.25 mi E
In "Applied" for 3 yr (since Nov 28, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $56,632,994 declared valuation across 1 permit).
- New home at 115 Erin Ct (Applied)0.25 mi E
In "Applied" for 3 yr (since Nov 28, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $55,415,888 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Hawkins Construction (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Anello Painting And Construction (1 on parcel, 1 in ½ mi · Commercial tenant improvement); Owner Builder (31 in ½ mi · Remodel / interior alteration); Haven Construction (16 in ½ mi · Accessory dwelling unit (new or conversion)); Owner (12 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 170630 | Remodel / interior alteration | Issued | Iss. Feb 11, 2022 | $125,000 | Convert Multi-Use Rooms To Rectory Residence |
| 143657 | Commercial tenant improvement | Issued | Iss. Aug 11, 2014 | $25,000 | Upgr 2 Bas For A D A (Complies With 11b-204.4, Exception #3) T.D. 7/14/14 |