605 Rosal Way
San Rafael 94903 · Santa Venetia · Unincorporated Marin · Coordinates: 38.01313, -122.51595
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AE flood / CAL FIRE moderate fire hazard severity zone (local responsibility area) due diligence; benchmark value $1,211,000 ($1,066,000–$1,356,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone R1-B1 allows residential use qualifying for ministerial ADU review under state law (1 ADU permit permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$22,342 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest Nov 3, 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)
- ! CAL FIRE Moderate Fire Hazard Severity Zone (Local Responsibility Area) (about 97% 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: New home at 16 Crestview Way (0.33 mi SW, 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 (~$14,377/yr at $1,211,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,198/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:
- 7,536 sq ft (0.17 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 605 ROSAL WAY
Zoning & Land Use
R1-B1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned R1-B1, a single-family residential zone. 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 R1-B1, a single-family residential zone. The lot is 7,536 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
- Moderate Fire Hazard Severity Zone (Local Responsibility Area) (about 97% of the lot, map Mar 24, 2025)
- FEMA National Flood Hazard Layer
- Zone AE: 1% annual chance flood (Special Flood Hazard Area) (all of the lot) · FIRM panel 06041C0294E, 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: $1,066,000 – $1,356,000 · 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 16 Crestview Way (Issued)0.33 mi SW
Active in "Issued" for 2.5 yr (first record May 20, 2024) with no new permit activity recorded in 15 mo. High-impact scale (1 housing unit, $770,000 declared valuation across 1 permit).
- New home at 35 Pt Gallinas Rd (Issued)0.48 mi E
Active in "Issued" for 9.5 yr (first record May 24, 2017) with no new permit activity recorded in 9.3 yr. High-impact scale (1 housing unit, $2,367,450 declared valuation across 1 permit).
- Accessory dwelling unit at 798 Hacienda Way (Applied)0.2 mi N
In "Applied" for 11.1 yr (since Oct 5, 2015), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Accessory dwelling unit at 835 Rosal Way (Applied)0.27 mi NE
In "Applied" for 2.2 yr (since Sep 11, 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: Jaj Roofing (3 on parcel, 3 in ½ mi · Solar / battery storage); West Coast Construction Pro Build (1 on parcel, 1 in ½ mi · Windows / doors / siding); Equinox Roofing Solutions (1 on parcel, 1 in ½ mi · Roof replacement); Owner Builder (40 in ½ mi · Remodel / interior alteration); Owner (20 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B48937 | Windows / doors / siding | Issued | Iss. Nov 3, 2026 | $19,000 | Siding Replacement |
| B48487 | Roof replacement | Issued | Iss. Sep 24, 2026 | $10,800 | ReRoofing |
| B44335 | Roof replacement | Issued | Iss. Oct 13, 2025 | $18,903 | Tear off 1 layer of existing comp shingles. Install 15 sqs of new comp shingles in standard color. — ReRoofing |
| B44256 | Solar / battery storage | Issued | Iss. Oct 7, 2025 | $18,903 | Tear off and disposal of one layer of existing comp shingle roof. Remove 16 solar panels, reinstall 15. One is currently… |
| B44148 | Solar / battery storage | Issued | Iss. Oct 1, 2025 |