315 Highland Ave
San Rafael 94901 · Country Club · Unincorporated Marin · Coordinates: 37.98043, -122.50349
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 $1,741,000 ($1,532,000–$1,950,000).
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 46,043 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 (+$7,040 contributory est.)
Public building records show issued construction/renovation work on this parcel (3 total permits, latest Nov 2, 2023).
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: Accessory dwelling unit at 41 Fairway Dr (adu 41a) (0.18 mi SE, 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 (~$20,472/yr at $1,741,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,706/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:
- 46,043 sq ft (1.06 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 315 HIGHLAND 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 46,043 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: $1,532,000 – $1,950,000 · 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
- Accessory dwelling unit at 41 Fairway Dr (adu 41a) (Issued)0.18 mi SE
Active in "Issued" for 23 mo (first record Dec 4, 2024) with no new permit activity recorded in 18 mo. High-impact scale (1 housing unit, $2,025,000 declared valuation across 1 permit).
- New home at 195 Fairway Dr (Issued)0.32 mi S
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)0.32 mi S
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)0.49 mi S
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).
Entity-resolved builders & contractors in ½ mile: Sunrun Installation Services (1 on parcel, 1 in ½ mi · Solar / battery storage); Project Roofing (1 on parcel, 1 in ½ mi · Roof replacement); No Ark Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (16 in ½ mi · New garage / accessory structure); Owner (9 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (3 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B35997 | Solar / battery storage | Issued | Iss. Nov 2, 2023 | $15,640 | PV on roof 5.6kW DC 6kW AC 14 mods (n) 9.8KWh ESS |
| B10784 | Roof replacement | Issued | Iss. Aug 8, 2016 | $13,500 | REROOF — ReRoofing |
| 149430 | Electrical / panel | Issued | Iss. Oct 14, 2015 | $1,000 | 200a Panel Change Out Only***Ext To 10-14-19 |