50 Alta Ave
Lagunitas 94938 · Lagunitas · Unincorporated Marin · Coordinates: 38.01698, -122.70369
Executive Verdict · Public-Records Synthesis
Zoned R1-B3-SGV in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $1,240,000 ($1,091,000–$1,389,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B3-SGV supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 16,640 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 (+$144,000 contributory est.)
Public building records show issued construction/renovation work on this parcel (3 total permits, latest Oct 7, 2025).
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)
- ! Delayed or open permit activity on this parcel
Demolition (91186): Pending in review for 3.4 yr (22.8× the 55d median) — slower than 90% of demolition permits in Unincorporated Marin (median 55d, 90th pct 261d, n=130).
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 (270 ft N, 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:
- 16,640 sq ft (0.38 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 50 ALTA AVE
Zoning & Land Use
R1-B3-SGV — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B3-SGV (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B3-SGV, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B3-SGV, a single-family residential zone. The lot is 16,640 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 (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 06041C0275D, 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: $1,091,000 – $1,389,000 · Status: Off market
HUD Small Area FMR (ZIP 94938) · FY 2026
Studio $2,170 · 1BR $2,610 · 2BR $3,150 · 3BR $4,020 · 4BR $4,200
Developments Deserving Closer Investigation & Active Area Builders
- Demolition (91186) (Applied)On this parcel
Pending in review for 3.4 yr (22.8× the 55d median) — slower than 90% of demolition permits in Unincorporated Marin (median 55d, 90th pct 261d, n=130).
- New home (Entitled)270 ft N
In "Entitled" for 2.1 yr (since Oct 4, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Remodel / interior alteration (180228) (Issued)On this parcel
Issued after 6 mo (2.2× the 83d median) — above the 75th percentile for remodel / interior alteration permits in Unincorporated Marin (median 83d, 75th pct 148d, n=1,054).
- Accessory dwelling unit at 5 Barranca Rd (Applied)0.34 mi N
In "Applied" for 7.8 yr (since Feb 7, 2019), 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 (1 on parcel, 8 in ½ mi · Accessory dwelling unit (new or conversion)); Thompson Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner (5 in ½ mi · Addition (adds square footage)); Juan Calmell (1 in ½ mi · New single-family home); Traditional Trades (1 in ½ mi · Addition (adds square footage)).
Permit & Project History on This Parcel (3 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 180228 | Remodel / interior alteration | Issued | Iss. Oct 7, 2025 | $300,000 | Remodel/Repair Fire Damage; Convert Lower Area To Utility; Reroof; Replace All Windows |
| B34528 | Electrical / panel | Issued | Iss. Jun 30, 2023 | $2,000 | Provide and install customer owned temporary power pole, including new, 100 amp, single phase 120/240 V electric service… |
| 91186 | Demolition | Applied | App. Jun 5, 2023 | $27,000 | Partial Demo Of Fire-Damaged S F D, Leave Foundations, Patio, Ret Walls |