329 Deertrail Ln
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.87460, -122.53148
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 $2,134,000 ($1,878,000–$2,390,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-2.5 allows residential use qualifying for ministerial ADU review under state law (4 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ 6 documented municipal building permits on file
On-parcel permit history is indexed through Apr 7, 2026, 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. 16.4 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)
about 1% 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)
- ! Delayed or open permit activity on this parcel
Other (94119): Pending in review for 7 mo — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,560).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 5 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 403 Marin Ave (adu 403a) (0.33 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)
Parcel & Assessor
- Lot size:
- 8,930 sq ft (0.21 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 329 DEERTRAIL LN
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 (about 1% of the lot); Zone X: minimal flood hazard (about 99% 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: $1,878,000 – $2,390,000 · 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
- Other (94119) (Applied)On this parcel
Pending in review for 7 mo — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,560).
- Accessory dwelling unit at 403 Marin Ave (adu 403a) (Issued)0.33 mi NW
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 535 Tennessee Valley Rd (adu 531) (Issued)0.34 mi SE
Active in "Issued" for 6 yr (first record Oct 29, 2020) with no new permit activity recorded in 4 yr. High-impact scale (1 housing unit, $800,000 declared valuation across 1 permit).
- New home at 407 Spruce St (Issued)0.4 mi NW
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).
Entity-resolved builders & contractors in ½ mile: Window And Door Factory Of California (1 on parcel, 1 in ½ mi · Windows / doors / siding); Astro Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Mayotyrone Plumbing (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Volta Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (60 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (6 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 94119 | Other | Applied | App. Apr 7, 2026 | $40,000 | Replace Elevated Deck |
| B46256 | Roof replacement | Issued | Iss. Mar 20, 2026 | $19,990 | ReRoofing; With Electronic Inspection |
| B45994 | Plumbing / water heater / sewer | Issued | Iss. Feb 25, 2026 | $8,350 | New Plumbing Fixture(s) |
| 93965 | General repair | Applied | App. Feb 2, 2026 | $34,680 | Foundation Retaining Wall |
| B45302 | Windows / doors / siding | Issued | Iss. Dec 31, 2025 | $25,000 | Replace 13 windows and 2 patio doors like for like. — Non-structural Door/Window Replacement |