253 Trinidad Dr
Tiburon 94920 · Paradise Cay · Unincorporated Marin · Coordinates: 37.91483, -122.47910
Executive Verdict · Public-Records Synthesis
Zoned RMP-1.35-BFC in Unincorporated Marin with likely ministerial ADU eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,885,000 ($2,539,000–$3,231,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-1.35-BFC allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$31,680 contributory est.)
Public building records show issued construction/renovation work on this parcel (2 total permits, latest May 12, 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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home at 149 Jamaica St (0.25 mi SE, 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 (~$33,628/yr at $2,885,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,802/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:
- 3,485 sq ft (0.08 ac)
- Assessor use:
- Single Family Attached
- Addresses on lot:
- 253 TRINIDAD DR
Zoning & Land Use
RMP-1.35-BFC — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-1.35-BFC (multifamily residential): state law allows ADUs where homes are allowed. On a multifamily lot the state allowance is different: ADUs in non-living space of the building, plus up to eight detached ADUs.
- SB 9: two homes on the lotUnlikely
Zoned RMP-1.35-BFC (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-1.35-BFC (multifamily residential), not a single-family residential zone.
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 06041C0486E, 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: $2,539,000 – $3,231,000 · 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 at 149 Jamaica St (Issued)0.25 mi SE
Active in "Issued" for 12.2 yr (first record Aug 19, 2014) with no new permit activity recorded in 12 yr. High-impact scale (1 housing unit, $750,000 declared valuation across 1 permit).
- New home at 4970 Ranch Rd (Issued)0.28 mi NW
Active in "Issued" for 11.4 yr (first record Jun 2, 2015) with no new permit activity recorded in 11.2 yr. High-impact scale (1 housing unit, $1,200,000 declared valuation across 1 permit).
- New home (Entitled)0.29 mi SE
In "Entitled" for 5.1 yr (since Oct 7, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home (Entitled)0.31 mi W
In "Entitled" for 8.5 yr (since May 17, 2018), 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: Alliance Custom Builders (1 on parcel, 2 in ½ mi · Remodel / interior alteration); Ernest Ongaro And Sons (1 on parcel, 1 in ½ mi · Other); Owner Builder (17 in ½ mi · Remodel / interior alteration); Owner (12 in ½ mi · Remodel / interior alteration); Davidson Builders (9 in ½ mi · New single-family home).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B46766 | Other | Issued | Iss. May 12, 2026 | $7,000 | Replace Mechanical Appliance |
| 152981 | Remodel / interior alteration | Issued | Iss. Aug 17, 2016 | $96,000 | Rmdl Kit, Repl Boiler And Stair Railing-Express |