22 Portola Ave
San Rafael 94903 · Santa Venetia · Unincorporated Marin · Coordinates: 37.99634, -122.52442
Executive Verdict · Public-Records Synthesis
Zoned R1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $1,201,000 ($1,057,000–$1,345,000).
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 7,710 sq ft lot. Local precedent is active with 2 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$9,504 contributory est.)
Public building records show issued construction/renovation work on this parcel (7 total permits, latest Jun 9, 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 Moderate 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 commercial building at 170 N San Pedro Rd (0.21 mi N, 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)
- ! Year 1 Prop 13 tax reset (~$14,262/yr at $1,201,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,188/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:
- 7,710 sq ft (0.18 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 22 PORTOLA AVE
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 7,710 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
- Moderate 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 06041C0457E, 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: $1,057,000 – $1,345,000 · 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
- New commercial building at 170 N San Pedro Rd (Issued)0.21 mi N
Active in "Issued" for 4.9 yr (first record Dec 1, 2021) with no new permit activity recorded in 4.4 yr. High-impact scale ($18,000,000 declared valuation across 1 permit).
- New home at 8 Edgehill Wy (Applied)360 ft SE
In "Applied" for 10.8 yr (since Feb 4, 2016), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Accessory dwelling unit at 59 San Pablo Ave (Applied)0.21 mi W
In "Applied" for 23 mo (since Nov 27, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Accessory dwelling unit at 15 Roosevelt Ave (Applied)0.27 mi N
In "Applied" for 4.3 yr (since Jul 13, 2022), 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: American Array Solar (3 on parcel, 3 in ½ mi · Other); Kelly Plumbing And Heating (3 on parcel, 3 in ½ mi · HVAC / heat pump); Walker Construction (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (28 in ½ mi · Remodel / interior alteration); Owner (11 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (7 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B47084 | Plumbing / water heater / sewer | Issued | Iss. Jun 9, 2026 | $5,000 | Replace Plumbing Fixtures(s) |
| B46715 | Other | Issued | Iss. May 8, 2026 | $800 | — |
| B41115 | Solar / battery storage | Issued | Iss. Feb 5, 2025 | $22,000 | ROOFTOP SOLAR PHTOVOLTAIC SYSTEM SIZE:6.90 KW-DC/11.50 KW-AC WITH INSTALLATION OF ESS SYSTEM SIZE:13.50 kWh 15-REC ALPHA… |
| B41005 | Roof replacement | Issued | Iss. Jan 27, 2025 | $8,500 | RE-ROOF COMP TO COMP SHINGLE, 34 SQUARES — ReRoofing |
| B25228 | HVAC / heat pump | Issued | Iss. Mar 22, 2021 | $5,000 |