130 Altena St
San Rafael 94901 · California Park · Unincorporated Marin · Coordinates: 37.95484, -122.51009
Executive Verdict · Public-Records Synthesis
Zoned R1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $1,602,000 ($1,410,000–$1,794,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 7,928 sq ft lot. Local precedent is active with 4 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$220,800 contributory est.)
Public building records show issued construction/renovation work on this parcel (7 total permits, latest May 15, 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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: 79 new homes at 0 Auburn St & Woodland Ave (0.28 mi N, applied). 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 (~$18,873/yr at $1,602,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,573/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:
- 7,928 sq ft (0.18 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 130 ALTENA ST
Zoning & Land Use
R1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1, a single-family residential zone. The lot is 7,928 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
- Not in a State-mapped fire hazard severity zone
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06041C0459F, effective March 16, 2016
- 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 94901) · FY 2026
Studio $2,150 · 1BR $2,580 · 2BR $3,120 · 3BR $3,990 · 4BR $4,130
Developments Deserving Closer Investigation & Active Area Builders
- 79 new homes at 0 Auburn St & Woodland Ave (Applied)0.28 mi N
In "Applied" for 23 mo (since Dec 18, 2024), exceeding the 292d median and 313d 90th percentile for new multifamily / condos / mixed-use permits in Unincorporated Marin (n=21). High-impact scale (79 housing units, 16 deed-restricted affordable across 16 permits).
- Demolition at 202 Auburn St (Applied)0.18 mi NW
In "Applied" for 4.2 yr (since Sep 14, 2022), exceeding the 55d median and 261d 90th percentile for demolition permits in Unincorporated Marin (n=130).
- New home (Entitled)0.29 mi W
In "Entitled" for 8.2 yr (since Sep 12, 2018), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Accessory dwelling unit at 134 Orange St (Applied)0.3 mi NW
In "Applied" for 5.2 yr (since Sep 8, 2021), 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 (1 on parcel, 5 in ½ mi · Remodel / interior alteration); Sunrun Installation Service (2 on parcel, 2 in ½ mi · Solar / battery storage); Resolute Design And Construction (1 on parcel, 1 in ½ mi · Addition (adds square footage)); William Gotelli Plumbing (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Moore Services (1 on parcel, 1 in ½ mi · HVAC / heat pump).
Permit & Project History on This Parcel (7 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B42257 | Solar / battery storage | Issued | Iss. May 15, 2025 | $3,500 | Removal and reinstall existing PV system to accommodate new roofing at existing location. |
| 178655 | Addition (adds square footage) | Issued | Iss. Feb 12, 2025 | $280,000 | New Second Story Addition W/ (2) Bedrms, Bathrm, & Bonus Rm |
| B24119 | Plumbing / water heater / sewer | Issued | Iss. Nov 9, 2020 | $4,710 | Replace existing tankless water heater with a tankless water heater in existing location — Replace Plumbing Fixtures(s) |
| 160814 | Solar / battery storage | Issued | Iss. Feb 21, 2019 | $5,000 | Battery Back-Up |
| 160813 | Solar / battery storage | Issued |