2381 Mar East St
Tiburon 94920 · Unincorporated Tiburon · Unincorporated Marin · Coordinates: 37.87681, -122.44420
Executive Verdict · Public-Records Synthesis
Zoned R2 in Unincorporated Marin with likely ministerial ADU eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,891,000 ($2,544,000–$3,238,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone R2 allows residential use qualifying for ministerial ADU review under state law (2 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$6,880 contributory est.)
Public building records show issued construction/renovation work on this parcel (6 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: New home (0.45 mi W, 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 (~$33,697/yr at $2,891,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,808/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:
- 3,964 sq ft (0.09 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 2381 MAR EAST ST
Zoning & Land Use
R2 — Residential Two Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R2 (two-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotCan't tell
Zoned R2 (two-family residential): we can't tell whether it counts as a single-family zone for SB 9. Residential Two Family.
- SB 9: split into two lotsCan't tell
Zoned R2 (two-family residential): we can't tell whether it counts as a single-family zone for SB 9. Residential Two Family.
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 06041C0489E, 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: $2,544,000 – $3,238,000 · Status: Off market
HUD Small Area FMR (ZIP 94920) · FY 2026
Studio $2,820 · 1BR $3,380 · 2BR $4,100 · 3BR $5,230 · 4BR $5,420
Developments Deserving Closer Investigation & Active Area Builders
- New home (Entitled)0.45 mi W
In "Entitled" for 2.2 yr (since Aug 13, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home (Entitled)0.45 mi W
In "Entitled" for 2.2 yr (since Aug 13, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home (Issued)480 ft W
Active in "Issued" for 2 yr (first record Oct 28, 2024) with no new permit activity recorded in 2 yr.
- Accessory dwelling unit at 2398 Vista Del Mar Ln (was 2401 Paradise Dr) (Issued)520 ft NW
Active in "Issued" for 6 yr (first record Nov 16, 2020) with no new permit activity recorded in 5.6 yr.
Entity-resolved builders & contractors in ½ mile: Sausalito Construction (2 on parcel, 3 in ½ mi · Remodel / interior alteration); Ernest Ongaro And Sons (3 on parcel, 3 in ½ mi · EV charger); Semper Solaris Construction (1 on parcel, 1 in ½ mi · Solar / battery storage); Owner Builder (8 in ½ mi · Accessory dwelling unit (new or conversion)); Owner (2 in ½ mi · Addition (adds square footage)).
Permit & Project History on This Parcel (6 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B42424 | Plumbing / water heater / sewer | Issued | Iss. May 15, 2025 | $2,400 | Replace tankless water heater, like for like, using existing connections — Replace Plumbing Fixtures(s) |
| B42068 | HVAC / heat pump | Issued | Iss. Apr 17, 2025 | $9,500 | Replace failed furnace with new furnace — Replace Mechanical Appliance |
| B42045 | EV charger | Issued | Iss. Apr 15, 2025 | $2,100 | Install 50 dedicated circuit and 50a Tesla EV charger, located in garage — EV Charging Station; With Electronic Inspecti… |
| B28627 | Solar / battery storage | Issued | Iss. Feb 4, 2022 | $18,200 | INSTALLING -13.5 kWh ENERGY STORAGE SYSTEM WITH 1 (N)-200A TESLA BACKUP GATEWAY 2 AND 1 (N)-TESLA POWERWALL 2 BATTERY BA… |
| 150947 |