684 Blackberry Ln
San Rafael 94903 · Marinwood · Unincorporated Marin · Coordinates: 38.02812, -122.55645
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 $1,325,000 ($1,166,000–$1,484,000).
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 8,799 sq ft lot. Local precedent is active with 1 ADU permit within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$31,440 contributory est.)
Public building records show issued construction/renovation work on this parcel (8 total permits, latest Nov 19, 2025).
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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 598 Loganberry Dr (adu 598a) (0.26 mi N, 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 (~$15,688/yr at $1,325,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,307/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:
- 8,799 sq ft (0.20 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 684 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 8,799 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 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: $1,166,000 – $1,484,000 · 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
- Accessory dwelling unit at 598 Loganberry Dr (adu 598a) (Issued)0.26 mi N
Active in "Issued" for 2.2 yr (first record Sep 6, 2024) with no new permit activity recorded in 22 mo. High-impact scale (1 housing unit, $830,000 declared valuation across 1 permit).
- New home (Entitled)0.24 mi SE
In "Entitled" for 6.6 yr (since Apr 8, 2020), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Accessory dwelling unit at 860 Idylberry Rd (Applied)0.27 mi W
In "Applied" for 5.5 yr (since May 28, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Demolition at 860 Appleberry Dr (Issued)0.31 mi SW
Active in "Issued" for 7 yr (first record Nov 18, 2019) with no new permit activity recorded in 7 yr.
Entity-resolved builders & contractors in ½ mile: Meadows Green Building And Des (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Armstrong Installation Service A California Corpor (1 on parcel, 1 in ½ mi · Roof replacement); Better Earth Electric (1 on parcel, 1 in ½ mi · Solar / battery storage); Ac Electric (1 on parcel, 1 in ½ mi · EV charger); Peter Levi Plumbing (1 on parcel, 1 in ½ mi · HVAC / heat pump).
Permit & Project History on This Parcel (8 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B44834 | Solar / battery storage | Issued | Iss. Nov 19, 2025 | $1,600 | Removal; of existing solar panels for a new roof and re-installation |
| B43065 | Roof replacement | Issued | Iss. Jul 10, 2025 | $29,800 | Sweep off existing roof material. Replace with foam overlay. 31 squares. — ReRoofing |
| B33767 | Solar / battery storage | Issued | Iss. May 15, 2023 | $13,464 | roof-mounted PV system size 7.2kW |
| B25151 | Plumbing / water heater / sewer | Issued | Iss. Mar 15, 2021 | $1,500 | provide power to new hot tub — New Circuits / Outlets |
| 164293 | Remodel / interior alteration | Issued | Iss. Feb 24, 2020 |