100 Old Railroad Grade Fire Rd
Mill Valley 94941 · Unincorporated Marin · Coordinates: 37.91999, -122.58870
Executive Verdict · Public-Records Synthesis
Zoned OA in Unincorporated Marin and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,181,000 ($1,854,000–$2,508,000).
Upsides & Opportunities
- ✓ 8 documented municipal building permits on file
On-parcel permit history is indexed through Apr 21, 2025, 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 High Fire Hazard Severity Zone (State Responsibility Area) (about 2% 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)
- ! Delayed or open permit activity on this parcel
New commercial building at 100 Old Railroad Grade Fire Rd: Active in "Issued" for 13.5 yr (first record May 9, 2013) with no new permit activity recorded in 11.1 yr.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! Year 1 Prop 13 tax reset (~$25,532/yr at $2,181,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,128/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:
- 23,916,836 sq ft (549.06 ac)
- Assessor use:
- Tax Exempt
- Addresses on lot:
- 100 OLD RAILROAD GRADE FIRE RD
Zoning & Land Use
OA — Open Area (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADUUnlikely
Zoned OA (open space): the zone doesn't allow homes, so state ADU rules don't apply.
- SB 9: two homes on the lotUnlikely
Zoned OA (open space), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned OA (open space), 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) (about 2% of the lot, map Apr 1, 2024); Very High Fire Hazard Severity Zone (State Responsibility Area) (about 98% of the lot, map Apr 1, 2024)
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06041C0465E, effective August 15, 2017
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $1,854,000 – $2,508,000 · 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
Nearby Activity (½ mile radius, since November 2024)
0 active or recent development projects and 2 total building permits recorded within ½ mile.
- Building systems1 permit
Developments Deserving Closer Investigation & Active Area Builders
- New commercial building at 100 Old Railroad Grade Fire Rd (Issued)On this parcel
Active in "Issued" for 13.5 yr (first record May 9, 2013) with no new permit activity recorded in 11.1 yr.
- Roof replacement (176785) (Issued)On this parcel
Issued after 5 mo — slower than 90% of roof replacement permits in Unincorporated Marin (median 0d, 90th pct 0d, n=3,663).
- Demolition (156254) (Issued)On this parcel
Issued after 14 mo (7.5× the 55d median) — slower than 90% of demolition permits in Unincorporated Marin (median 55d, 90th pct 261d, n=130).
Entity-resolved builders & contractors in ½ mile: Northbay Roofing And Gutters (2 on parcel, 2 in ½ mi · Roof replacement); Hoffmann Construction (2 on parcel, 2 in ½ mi · Demolition); The Electrician (1 on parcel, 1 in ½ mi · Electrical / panel); Green Leaf Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Giovacchini Construction (1 on parcel, 1 in ½ mi · Roof replacement).
Permit & Project History on This Parcel (8 permits, 1 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 179094 | Other | Issued | Iss. Apr 21, 2025 | $9,800 | Move Existing Propane Tank |
| B38362 | Roof replacement | Issued | Iss. Jun 11, 2024 | $32,998 | Tear off existing comp shingles install new Class A comp SHingles. 22 squares or 2200 sqft — ReRoofing; With Electronic … |
| 176785 | Roof replacement | Issued | Iss. Jun 4, 2024 | $14,232 | Reroof; Repair To (E) Truss System |
| B36460 | Roof replacement | Issued | Iss. Dec 28, 2023 | $77,000 | Composition shingle roof to be replaced with like class a composition shingles for 50squares @ 8/12 pitch. New TPO roofi… |