20 Westgate Dr
San Rafael 94903 · Lucas Valley · Unincorporated Marin · Coordinates: 38.04022, -122.59760
Executive Verdict · Public-Records Synthesis
Zoned RMP-0.345 in Unincorporated Marin with likely ministerial ADU eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $1,560,000 ($1,373,000–$1,747,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-0.345 allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$57,260 contributory est.)
Public building records show issued construction/renovation work on this parcel (11 total permits, latest Oct 22, 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 (State 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 Apr 1, 2024)
- ! 2 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 71 Creekside Dr (0.18 mi SE, 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 (~$18,390/yr at $1,560,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,533/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:
- 40,032 sq ft (0.92 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 20 WESTGATE DR
Zoning & Land Use
RMP-0.345 — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-0.345 (multifamily residential): state law allows ADUs where homes are allowed. On a multifamily lot the state allowance is different: ADUs in non-living space of the building, plus up to eight detached ADUs.
- SB 9: two homes on the lotUnlikely
Zoned RMP-0.345 (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-0.345 (multifamily residential), not a single-family residential zone.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- High Fire Hazard Severity Zone (State Responsibility Area) (all of the lot, map Apr 1, 2024)
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06041C0286D, 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: $1,373,000 – $1,747,000 · 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 71 Creekside Dr (Applied)0.18 mi SE
In "Applied" for 5.3 yr (since Aug 12, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Accessory dwelling unit at 12 Red Cedar Ct (Issued)0.48 mi E
Active in "Issued" for 2.6 yr (first record Mar 25, 2024) with no new permit activity recorded in 2.6 yr.
Entity-resolved builders & contractors in ½ mile: Owner Builder (4 on parcel, 6 in ½ mi · New garage / accessory structure); Marin County Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Owner (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Pac Solar (1 on parcel, 1 in ½ mi · Solar / battery storage); Divine Electric (1 on parcel, 1 in ½ mi · Other).
Permit & Project History on This Parcel (11 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 182807 | New garage / accessory structure | Issued | Iss. Oct 22, 2026 | $75,000 | New Single Story Detached Non-Conditioned Two Car Garage Type V Structure. |
| B35754 | Other | Issued | Iss. Oct 12, 2023 | $16,033 | 26KW Generac Generator Install |
| 174497 | Remodel / interior alteration | Issued | Iss. Jul 13, 2023 | $75,000 | Remodel: Kitchen, Remove (3) Wood Burning & Replace W/ Gas Fireplaces |
| B23313 | Roof replacement | Issued | Iss. Aug 20, 2020 | $3,150 | RE-ROOF THE SMALL SOUTH FACING FLAT ROOF ON RESIDENCE WITH CLASS A FIRE RATE (TPO) GRAY COLOR, INSTALL 2 SQUARES TOTAL. … |
| 159637 | New garage / accessory structure | Issued |