307 Summit Ave
San Rafael 94901 · Country Club · Unincorporated Marin · Coordinates: 37.97523, -122.50456
Executive Verdict · Public-Records Synthesis
Zoned R1-B4 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (local responsibility area) due diligence; benchmark value $1,734,000 ($1,526,000–$1,942,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B4 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 48,395 sq ft lot. Local precedent is active with 4 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ 2 documented municipal building permits on file
On-parcel permit history is indexed through Feb 25, 2026, letting you verify roof, HVAC, electrical, or structural work against seller disclosures.
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 Moderate 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: New home at 195 Fairway Dr (450 ft NE, 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 (~$20,391/yr at $1,734,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,699/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:
- 48,395 sq ft (1.11 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 307 SUMMIT AVE
Zoning & Land Use
R1-B4 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B4 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B4, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B4, a single-family residential zone. The lot is 48,395 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
- Moderate 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 06041C0457E, 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: $1,526,000 – $1,942,000 · Status: Off market
HUD Small Area FMR (ZIP 94901) · FY 2026
Studio $2,150 · 1BR $2,580 · 2BR $3,120 · 3BR $3,990 · 4BR $4,130
Developments Deserving Closer Investigation & Active Area Builders
- New home at 195 Fairway Dr (Issued)450 ft NE
Active in "Issued" for 5.6 yr (first record Mar 22, 2021) with no new permit activity recorded in 5.5 yr. High-impact scale (1 housing unit, $1,400,000 declared valuation across 1 permit).
- New home at 195 Fairway Dr (Issued)450 ft NE
Active in "Issued" for 12.9 yr (first record Dec 26, 2013) with no new permit activity recorded in 10.4 yr. High-impact scale (1 housing unit, $1,636,842 declared valuation across 2 permits).
- New home at 53 Montecito Rd (Issued)0.24 mi SE
Active in "Issued" for 8.9 yr (first record Dec 27, 2017) with no new permit activity recorded in 8.5 yr. High-impact scale (1 housing unit, $1,498,000 declared valuation across 1 permit).
- New home at 40 Montecito Rd (aka 40a) (Issued)0.26 mi SE
Active in "Issued" for 5.3 yr (first record Jul 16, 2021) with no new permit activity recorded in 3.9 yr. High-impact scale (1 housing unit, $2,515,850 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Owner (1 on parcel, 19 in ½ mi · Remodel / interior alteration); Rocky Hill Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (27 in ½ mi · Remodel / interior alteration); Coastal Construction (4 in ½ mi · New garage / accessory structure); Sausalito Construction (3 in ½ mi · New single-family home).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B45993 | Electrical / panel | Issued | Iss. Feb 25, 2026 | $5,829 | Replace Circuits / Outlets |
| B30088 | Roof replacement | Issued | Iss. Jun 17, 2022 | $32,800 | Re-roof — ReRoofing |