4 Walsh Dr
Mill Valley 94941 · Muir Woods Park · Unincorporated Marin · Coordinates: 37.90137, -122.55866
Executive Verdict · Public-Records Synthesis
Zoned RMP-0.5 in Unincorporated Marin with likely ministerial ADU eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,322,000 ($2,043,000–$2,601,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-0.5 allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$43,591 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest Jun 6, 2022).
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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home at 65 Ridge Ave (0.41 mi SW, 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 (~$27,153/yr at $2,322,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,263/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:
- 23,914 sq ft (0.55 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 4 WALSH DR
Zoning & Land Use
RMP-0.5 — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-0.5 (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-0.5 (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-0.5 (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 06041C0468F, 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: $2,043,000 – $2,601,000 · Status: Off market
HUD Small Area FMR (ZIP 94941) · FY 2026
Studio $2,730 · 1BR $3,270 · 2BR $3,960 · 3BR $5,060 · 4BR $5,240
Developments Deserving Closer Investigation & Active Area Builders
- New home at 65 Ridge Ave (Applied)0.41 mi SW
In "Applied" for 4 yr (since Oct 27, 2022), 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, $3,000,000 declared valuation across 1 permit).
- Demolition at 688 Sequoia Valley Rd (Applied)0.26 mi S
In "Applied" for 3.2 yr (since Sep 6, 2023), exceeding the 55d median and 261d 90th percentile for demolition permits in Unincorporated Marin (n=130).
- Attached ADU (Entitled)0.47 mi NE
In "Entitled" for 3.9 yr (since Dec 22, 2022), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home at 49 Ridge Ave (Applied)0.47 mi SW
In "Applied" for 5.1 yr (since Oct 15, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Entity-resolved builders & contractors in ½ mile: Robert Federighi (1 on parcel, 2 in ½ mi · Addition (adds square footage)); J And J Electric (1 on parcel, 1 in ½ mi · Solar / battery storage); Marin Kitchen (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Haddon Heating And Cooling (1 on parcel, 1 in ½ mi · HVAC / heat pump); Ongaro Ernest And Sons (1 on parcel, 1 in ½ mi · HVAC / heat pump).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 171620 | Solar / battery storage | Issued | Iss. Jun 6, 2022 | $55,000 | 11.2kw Rooftop Photovoltaic & Energy Storage System - Express |
| B23038 | HVAC / heat pump | Issued | Iss. Jul 20, 2020 | $7,409 | AC Replacement 16 SEER — Replace Mechanical Appliance |
| 160558 | Remodel / interior alteration | Issued | Iss. Jan 17, 2019 | $28,968 | Kitch Rmdl, Elect Upgrade Express |
| 159044 | Addition (adds square footage) | Issued | Iss. Jul 16, 2018 | $19,000 | Remove Existing Header, Rmdl Bath T.D. 6/13/18 |
| 149062 | HVAC / heat pump | Issued | Iss. Sep 21, 2015 |