327 Cardinal Ct
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.87956, -122.52679
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AE flood due diligence; benchmark value $2,071,000 ($1,822,000–$2,320,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone R1-B1 allows residential use qualifying for ministerial ADU review under state law (9 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ 2 documented municipal building permits on file
On-parcel permit history is indexed through Feb 2, 2025, letting you verify roof, HVAC, electrical, or structural work against seller disclosures.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Tamalpais
50 substantial renovation & housing permits over 24 months (20.5 per 1,000 parcels vs. 16.4 citywide baseline) (#3 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Tamalpais)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (AE, about 17% of the lot of lot)
Zone AE: regulatory floodway (Special Flood Hazard Area) overlaps this parcel. Expect mandatory flood insurance for federally backed loans and floodplain elevation/mitigation rules for new units or SB 9 applications.
Source: FEMA National Flood Hazard Layer (parcel polygon)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New commercial building at 201 Flamingo Rd (aka 205) (0.11 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 (~$24,267/yr at $2,071,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,022/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:
- 6,098 sq ft (0.14 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 327 CARDINAL CT
Zoning & Land Use
R1-B1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned R1-B1, a single-family residential zone. FEMA regulatory floodway covers about 17% of the lot: SB 9 requires a no-rise certification.
- SB 9: split into two lotsPossible, with conditions
Zoned R1-B1, a single-family residential zone. The lot is 6,098 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original. FEMA regulatory floodway covers about 17% of the lot: SB 9 requires a no-rise certification.
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 AE: regulatory floodway (Special Flood Hazard Area) (about 17% of the lot); Zone AE: 1% annual chance flood (Special Flood Hazard Area) (about 83% of the lot) · FIRM panel 06041C0469F, 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: $1,822,000 – $2,320,000 · Status: Off market
HUD Small Area FMR (ZIP 94941) · FY 2026
Studio $2,730 · 1BR $3,270 · 2BR $3,960 · 3BR $5,060 · 4BR $5,240
Developments Deserving Closer Investigation & Active Area Builders
- New commercial building at 201 Flamingo Rd (aka 205) (Issued)0.11 mi N
Active in "Issued" for 11.7 yr (first record Feb 17, 2015) with no new permit activity recorded in 11.2 yr. High-impact scale ($3,938,400 declared valuation across 3 permits).
- New home at 334 Dolan Ave (Issued)0.19 mi NW
Active in "Issued" for 8.2 yr (first record Sep 5, 2018) with no new permit activity recorded in 8 yr. High-impact scale (1 housing unit, $759,000 declared valuation across 1 permit).
- New home at 222 Beryl St (Issued)0.37 mi N
Active in "Issued" for 11.9 yr (first record Dec 23, 2014) with no new permit activity recorded in 10 yr. High-impact scale (1 housing unit, $900,000 declared valuation across 1 permit).
- New home at 217 Cleveland Ave (Issued)0.39 mi N
Active in "Issued" for 9.7 yr (first record Feb 21, 2017) with no new permit activity recorded in 2.3 yr. High-impact scale (1 housing unit, $875,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Brendan Roofing And Waterproofing (1 on parcel, 1 in ½ mi · Roof replacement); Jm Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (71 in ½ mi · Remodel / interior alteration); Owner (49 in ½ mi · Remodel / interior alteration); International Building Investment (12 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B41084 | Electrical / panel | Issued | Iss. Feb 2, 2025 | $4,200 | REPLACE THE ZINSCO MAIN METER PANEL AT THE FRONT OF THE HOUSE. UPGRADE FROM 100AMPS TO 200AMPS. — Service Upgrade |
| B38151 | Roof replacement | Issued | Iss. May 22, 2024 | $17,000 | Complete roof replacement and tear off — ReRoofing |