595 Blackberry Ln
San Rafael 94903 · Marinwood · Unincorporated Marin · Coordinates: 38.02799, -122.55464
Executive Verdict · Public-Records Synthesis
Zoned R1 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 $1,329,000 ($1,170,000–$1,488,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 8,015 sq ft lot. Local precedent is active with 2 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$44,880 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest May 15, 2026).
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) (about 72% 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 3 Erin Dr (0.48 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 (~$15,734/yr at $1,329,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,311/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:
- 8,015 sq ft (0.18 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 595 BLACKBERRY LN
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 lotLikely eligible
Zoned R1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1, a single-family residential zone. The lot is 8,015 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) (about 72% of the lot, map Mar 24, 2025); Moderate Fire Hazard Severity Zone (Local Responsibility Area) (about 28% of the lot, map Mar 24, 2025)
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all 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: $1,170,000 – $1,488,000 · 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 3 Erin Dr (Applied)0.48 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 118 Erin Ct (Applied)0.48 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 111 Erin Ct (Applied)0.48 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)0.48 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: Tim Lawlor Construction (1 on parcel, 2 in ½ mi · Other); Ernest Ongaro And Sons (2 on parcel, 2 in ½ mi · HVAC / heat pump); Pesa Construction (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Papas Plumbing (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Owner Builder (31 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B46780 | Other | Issued | Iss. May 15, 2026 | $75,000 | — |
| B41368 | HVAC / heat pump | Issued | Iss. Feb 24, 2025 | $10,600 | Replace 3 zone ductless mini split with new 3 zone ductless mini split — Replace Mechanical Appliance |
| 169079 | Plumbing / water heater / sewer | Issued | Iss. Aug 12, 2021 | $2,000 | Gas Line For Bbq & Firepit T.D. 8-16-21 |
| B26389 | HVAC / heat pump | Issued | Iss. Jul 22, 2021 | $9,000 | replace failed ductless mini split with new ductless mini split (3 zones) — Replace Mechanical Appliance |
| 157557 | Remodel / interior alteration | Issued | Iss. Jan 29, 2018 |