6 Valleystone Dr
San Rafael 94903 · Marinwood · Unincorporated Marin · Coordinates: 38.03933, -122.54959
Executive Verdict · Public-Records Synthesis
Zoned R1-B2 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE high fire hazard severity zone (local responsibility area) due diligence; benchmark value $1,350,000 ($1,188,000–$1,512,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B2 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 12,110 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$24,313 contributory est.)
Public building records show issued construction/renovation work on this parcel (8 total permits, latest Apr 22, 2024).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
Watchouts & Due Diligence
- ! Mapped flood awareness zone (Zone X: minimal flood hazard)
all of the lot of the parcel intersects Zone X: minimal flood hazard. Outside mandatory federal SFHA insurance rules, but check local drainage and finished-floor requirements.
Source: FEMA National Flood Hazard Layer (parcel polygon)
- ! CAL FIRE High Fire Hazard Severity Zone (Local Responsibility Area) (all 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)
- ! 4 slow or stalled nearby projects within ½ mile
Closest lead: 125 new homes (0.45 mi E, entitled). 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 (~$15,975/yr at $1,350,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,331/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:
- 12,110 sq ft (0.28 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 6 VALLEYSTONE DR
Zoning & Land Use
R1-B2 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B2 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B2, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B2, a single-family residential zone. The lot is 12,110 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- High Fire Hazard Severity Zone (Local Responsibility Area) (all of the lot, map Mar 24, 2025)
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06041C0291D, effective May 4, 2009
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $1,188,000 – $1,512,000 · 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
- 125 new homes (Entitled)0.45 mi E
In "Entitled" for 23 mo (since Dec 6, 2024), exceeding the 292d median and 313d 90th percentile for new multifamily / condos / mixed-use permits in Unincorporated Marin (n=21). High-impact scale (125 housing units, 124 deed-restricted affordable across 0 permits).
- Accessory dwelling unit at 2558 Heatherstone Dr (Applied)0.45 mi SE
In "Applied" for 5.5 yr (since Apr 29, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Accessory dwelling unit at 287 Blackstone Dr (Issued)0.48 mi E
Active in "Issued" for 19 mo (first record Apr 23, 2025) with no new permit activity recorded in 14 mo.
- Accessory dwelling unit at 437 Pinewood Dr (Issued)0.48 mi S
Active in "Issued" for 10.1 yr (first record Oct 17, 2016) with no new permit activity recorded in 9.7 yr.
Entity-resolved builders & contractors in ½ mile: Solarcraft Services (5 on parcel, 5 in ½ mi · Solar / battery storage); Juan Calmell (2 on parcel, 2 in ½ mi · General repair); Wedge Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Owner Builder (26 in ½ mi · Remodel / interior alteration); Owner (18 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (8 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B37759 | Roof replacement | Issued | Iss. Apr 22, 2024 | $18,500 | Remove existing 28 sq ft roof down to sheathing. Prepare existing for new roof. Install Malarkey Legacy Shingles. — ReRo… |
| B37655 | Solar / battery storage | Issued | Iss. Apr 12, 2024 | $21,979 | (NEW) 13.5 kWh BATTERY STORAGE ADDED TO (EXISTING) PV & ESS |
| 164665 | Solar / battery storage | Issued | Iss. May 20, 2020 | $28,000 | Photovolaic 2.56 Kw, (60.1) Ess |
| 152266 | Electrical / panel | Issued | Iss. Jun 9, 2016 | $1,000 | Main Panel Upgr From 100 A To 125 A |
| 151929 | Solar / battery storage | Issued | Iss. May 11, 2016 |