125 A Mt Lassen Dr
San Rafael 94903 · Lucas Valley · Unincorporated Marin · Coordinates: 38.02957, -122.57074
Executive Verdict · Public-Records Synthesis
Zoned R1-B-LV in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE high fire hazard severity zone (local responsibility area) due diligence; benchmark value $1,602,000 ($1,410,000–$1,794,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B-LV supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 9,191 sq ft lot. Local precedent is active with 1 ADU permit within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$207,193 contributory est.)
Public building records show issued construction/renovation work on this parcel (4 total permits, latest Oct 26, 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 (Local 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 Mar 24, 2025)
- ! Delayed or open permit activity on this parcel
Accessory dwelling unit at 125 Mt Lassen Dr (adu 125a): Active in "Issued" for 23 mo (first record Dec 11, 2024) with no new permit activity recorded in 12 mo.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 4 slow or stalled nearby projects within ½ mile
Closest lead: New home (0.22 mi SE, entitled). 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:
- 9,191 sq ft (0.21 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 125A MT LASSEN DR; 125 MT LASSEN DR
Zoning & Land Use
R1-B-LV — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B-LV (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B-LV, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B-LV, a single-family residential zone. The lot is 9,191 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- High Fire Hazard Severity Zone (Local Responsibility Area) (all of the lot, map Mar 24, 2025)
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06041C0289D, 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: $1,410,000 – $1,794,000 · 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 125 Mt Lassen Dr (adu 125a) (Issued)On this parcel
Active in "Issued" for 23 mo (first record Dec 11, 2024) with no new permit activity recorded in 12 mo.
- New home (Entitled)0.22 mi SE
In "Entitled" for 2.9 yr (since Dec 7, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home (Entitled)0.22 mi SE
In "Entitled" for 3.3 yr (since Jul 10, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home (Entitled)0.22 mi SE
In "Entitled" for 3.8 yr (since Jan 14, 2023), 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: Owner Builder (2 on parcel, 21 in ½ mi · Remodel / interior alteration); Owner (1 on parcel, 4 in ½ mi · Remodel / interior alteration); Hooked On Solar (1 on parcel, 1 in ½ mi · Other); Tim Lawlor Construction (6 in ½ mi · Remodel / interior alteration); Marin Kitchen Works (5 in ½ mi · Addition (adds square footage)).
Permit & Project History on This Parcel (4 permits, 1 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B48900 | Other | Issued | Iss. Oct 26, 2026 | $11,410 | — |
| 180528 | Accessory dwelling unit (new or conversion) | Issued | Iss. Nov 19, 2025 | $56,500 | New Detached A D U; Main Panel Upgrade; Landing |
| B43163 | Electrical / panel | Issued | Iss. Jul 21, 2025 | $250 | Install two new receptacle circuits and one new lighting circuit in a exterior retaining wall. — New Circuits / Outlets |
| 179144 | General repair | Issued | Iss. Apr 29, 2025 | $4,789 | New Concrete Retaining Wall |