280 Flamingo Rd
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.87807, -122.52703
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AH flood / CAL FIRE moderate fire hazard severity zone (local responsibility area) due diligence; benchmark value $2,094,000 ($1,843,000–$2,345,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone R1-B1 allows residential use qualifying for ministerial ADU review under state law (5 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$16,170 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest Feb 24, 2022).
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 (AH, all of the lot of lot)
Zone AH: 1% annual chance flood (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)
- ! CAL FIRE Moderate Fire Hazard Severity Zone (Local Responsibility Area) (about 34% 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 Mar 24, 2025)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New commercial building at 201 Flamingo Rd (aka 205) (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 (~$24,531/yr at $2,094,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,044/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:
- 6,360 sq ft (0.15 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 280 FLAMINGO RD
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 Special Flood Hazard Area (Zone AH) covers all of the lot: the project must meet the National Flood Insurance Program floodplain standards, or the lot needs a map revision.
- SB 9: split into two lotsPossible, with conditions
Zoned R1-B1, a single-family residential zone. The lot is 6,360 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original. FEMA Special Flood Hazard Area (Zone AH) covers all of the lot: the project must meet the National Flood Insurance Program floodplain standards, or the lot needs a map revision.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Moderate Fire Hazard Severity Zone (Local Responsibility Area) (about 34% of the lot, map Mar 24, 2025)
- FEMA National Flood Hazard Layer
- Zone AH: 1% annual chance flood (Special Flood Hazard Area) (all 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: $1,843,000 – $2,345,000 · 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)0.21 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)0.25 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 535 Tennessee Valley Rd (adu 531) (Issued)0.4 mi S
Active in "Issued" for 6 yr (first record Oct 29, 2020) with no new permit activity recorded in 4 yr. High-impact scale (1 housing unit, $800,000 declared valuation across 1 permit).
- New home at 222 Beryl St (Issued)0.47 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).
Entity-resolved builders & contractors in ½ mile: Owner (1 on parcel, 40 in ½ mi · Remodel / interior alteration); Michael J Butler (1 on parcel, 1 in ½ mi · Addition (adds square footage)); Valerie Saroyan (1 on parcel, 1 in ½ mi · HVAC / heat pump); Fast Water Heater (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Cbs Electric (1 on parcel, 1 in ½ mi · Electrical / panel).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 170731 | Remodel / interior alteration | Issued | Iss. Feb 24, 2022 | $35,000 | Remodel Kitchen |
| B25995 | HVAC / heat pump | Issued | Iss. Jun 17, 2021 | $22,000 | -Cosmetic upgrade to 1 bathroom. (Existing plumbing and electric to remain) -Replace existing shower in 1 bathroom. -Rel… |
| 146492 | Addition (adds square footage) | Issued | Iss. Apr 2, 2015 | $125,000 | Addition W/New Deck T.D. 11/28/14 |
| 142515 | Electrical / panel | Issued | Iss. May 7, 2014 | $1,785 | Electrical Upgrade From 100 To 125amps |
| 142045 | Plumbing / water heater / sewer | Issued | Iss. Mar 27, 2014 |