2457 Mar East St
Tiburon 94920 · Unincorporated Tiburon · Unincorporated Marin · Coordinates: 37.87773, -122.44446
Executive Verdict · Public-Records Synthesis
Zoned R2 in Unincorporated Marin with likely ministerial ADU eligibility and mapped CAL FIRE moderate fire hazard severity zone (local responsibility area) due diligence; benchmark value $3,070,000 ($2,702,000–$3,438,000).
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 (+$99,000 contributory est.)
Public building records show issued construction/renovation work on this parcel (2 total permits, latest Jan 6, 2021).
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 (Local 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 Mar 24, 2025)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home (0.46 mi SW, 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 (~$35,755/yr at $3,070,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,980/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:
- 5,706 sq ft (0.13 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 2457 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
- Moderate Fire Hazard Severity Zone (Local Responsibility Area) (all of the lot, map Mar 24, 2025)
- 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: $2,702,000 – $3,438,000 · 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)0.46 mi SW
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)0.46 mi SW
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).
- Accessory dwelling unit at 2398 Vista Del Mar Ln (was 2401 Paradise Dr) (Issued)370 ft W
Active in "Issued" for 6 yr (first record Nov 16, 2020) with no new permit activity recorded in 5.6 yr.
- New home (Issued)510 ft SW
Active in "Issued" for 2 yr (first record Oct 28, 2024) with no new permit activity recorded in 2 yr.
Entity-resolved builders & contractors in ½ mile: Sausalito Construction (1 on parcel, 3 in ½ mi · Remodel / interior alteration); Lighthouse Const Service (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Owner Builder (8 in ½ mi · Accessory dwelling unit (new or conversion)); Owner (2 in ½ mi · Addition (adds square footage)); Deetken Construction (2 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 166781 | Remodel / interior alteration | Issued | Iss. Jan 6, 2021 | $225,000 | Rmdl Kit, Rmv Beam; Rmdl Master Bath & Closet; Rpl Sub-Panel T.D. 11-24-20 |
| 141308 | General repair | Issued | Iss. Jan 22, 2014 | $27,750 | Repair Drywall, Underlayment Under Carpet And Hardwood Floor Due To Water Damage |