406 Countyview Dr
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.87293, -122.53513
Executive Verdict · Public-Records Synthesis
Zoned RMP-2.5 in Unincorporated Marin with likely ministerial ADU eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $1,947,000 ($1,713,000–$2,181,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-2.5 allows residential use qualifying for ministerial ADU review under state law (1 ADU permit permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ 5 documented municipal building permits on file
On-parcel permit history is indexed through Jun 29, 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)
- ✓ Above-average reinvestment in Tamalpais
50 substantial renovation & housing permits over 24 months (20.5 per 1,000 parcels vs. 16.3 citywide baseline) (#3 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Tamalpais)
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 469 W Live Oak Dr (aka 461) (0.35 mi NW, 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 (~$22,841/yr at $1,947,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,903/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:
- 2,875 sq ft (0.07 ac)
- Assessor use:
- Single Family Attached
- Addresses on lot:
- 406 COUNTYVIEW DR
Zoning & Land Use
RMP-2.5 — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-2.5 (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-2.5 (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-2.5 (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 06041C0510E, 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: $1,713,000 – $2,181,000 · 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 469 W Live Oak Dr (aka 461) (Issued)0.35 mi NW
Active in "Issued" for 6.1 yr (first record Oct 22, 2020) with no new permit activity recorded in 22 mo. High-impact scale (1 housing unit, $980,000 declared valuation across 1 permit).
- Accessory dwelling unit at 403 Marin Ave (adu 403a) (Issued)0.35 mi N
Active in "Issued" for 2.9 yr (first record Dec 21, 2023) with no new permit activity recorded in 19 mo. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
- New home at 407 Spruce St (Issued)0.43 mi N
Active in "Issued" for 7.7 yr (first record Mar 14, 2019) with no new permit activity recorded in 7.5 yr. High-impact scale (1 housing unit, $750,000 declared valuation across 1 permit).
- New home at 760 Bay Rd (Issued)0.45 mi NW
Active in "Issued" for 9.4 yr (first record Jun 12, 2017) with no new permit activity recorded in 8.4 yr. High-impact scale (1 housing unit, $750,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Xmag Construction (3 on parcel, 5 in ½ mi · Other); Crown Ridge Roofing (1 on parcel, 1 in ½ mi · Roof replacement); J Power Electrical (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (47 in ½ mi · Remodel / interior alteration); Owner (27 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B42650 | Other | Issued | Iss. Jun 29, 2025 | $10,000 | Install new fireplace insert |
| B41789 | Other | Issued | Iss. Mar 29, 2025 | $40,000 | Minor kitchen and bath remodel |
| B41579 | Electrical / panel | Issued | Iss. Mar 12, 2025 | $10,000 | Furnish and install (1) 400 AMP, 120-240 Volts 3-wire single meter service lateral. Demo of the old 100 AMP Service Run … |
| B41379 | Windows / doors / siding | Issued | Iss. Feb 25, 2025 | $20,000 | Remove and replace 2 leaky windows over kitchen and living room. Remove replace in kind any framing or components that c… |
| B22194 | Roof replacement | Issued | Iss. Feb 28, 2020 |