230 Alta Ave
Lagunitas 94938 · Lagunitas · Unincorporated Marin · Coordinates: 38.01422, -122.70351
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 $1,135,000 ($999,000–$1,271,000).
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 26,354 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 (+$6,720 contributory est.)
Public building records show issued construction/renovation work on this parcel (3 total permits, latest Nov 7, 2022).
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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home (0.24 mi 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)
- ! Year 1 Prop 13 tax reset (~$13,503/yr at $1,135,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,125/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:
- 26,354 sq ft (0.61 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 230 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 26,354 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: $999,000 – $1,271,000 · 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
- New home (Entitled)0.24 mi 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).
- Demolition at 138 Rodeo Ave (Issued)480 ft E
Active in "Issued" for 12.8 yr (first record Feb 10, 2014) with no new permit activity recorded in 12.8 yr.
- New home at 152 Alta Ave (Issued)0.13 mi NW
Active in "Issued" for 19 mo (first record Apr 1, 2025) with no new permit activity recorded in 14 mo.
- New home at 5 Charles Ln (Issued)0.19 mi S
Active in "Issued" for 16.9 yr (first record Dec 31, 2009) with no new permit activity recorded in 11.8 yr.
Entity-resolved builders & contractors in ½ mile: Solar Roofing (2 on parcel, 2 in ½ mi · Roof replacement); Sunrun Installation Services (1 on parcel, 1 in ½ mi · Solar / battery storage); Owner Builder (7 in ½ mi · Remodel / interior alteration); Owner (7 in ½ mi · Demolition); Gerrit Roze Construction (3 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 |
|---|---|---|---|---|---|
| B31539 | Roof replacement | Issued | Iss. Nov 7, 2022 | $10,000 | REROOF, 5/12 PITCH, LIKE FOR LIKE SHINGLES 6 SQUARES FOR THE DETACHED GARAGE, CRRC PRODUCT ID # 0668-0119 — ReRoofing |
| B30198 | Roof replacement | Issued | Iss. Jun 27, 2022 | $22,395 | Whole roof tear-off — ReRoofing |
| B29873 | Solar / battery storage | Issued | Iss. May 27, 2022 | $15,000 | Install (17) roof mount solar panels at 5.95kw. Install new 100A main panel and new 100A main breaker with 125A busbar. |