53 Dolphin Isle
Novato 94949 · Bel Marin Keys · Unincorporated Marin · Coordinates: 38.07658, -122.51541
Executive Verdict · Public-Records Synthesis
Zoned RSP-1.6-BFC in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AE flood due diligence; benchmark value $1,383,000 ($1,217,000–$1,549,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RSP-1.6-BFC allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$33,865 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest Oct 23, 2025).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (AE, about 42% of the lot of lot)
Zone AE: 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)
- ! Delayed or open permit activity on this parcel
Windows / doors / siding (147491): Issued after 2 mo — slower than 90% of windows / doors / siding permits in Unincorporated Marin (median 0d, 90th pct 5d, n=1,476).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 3 slow or stalled nearby projects within ½ mile
Closest lead: Demolition at 18 Dolphin Isle (480 ft NW, 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 (~$16,355/yr at $1,383,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,363/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:
- 9,670 sq ft (0.22 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 53 DOLPHIN ISLE
Zoning & Land Use
RSP-1.6-BFC — Residential Single Family Planned (Unincorporated Marin)
Undesignated — Undesignated (Novato)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RSP-1.6-BFC (single-family residential): state law allows ADUs where homes are allowed. The parcel point also falls in Undesignated.
- SB 9: two homes on the lotPossible, with conditions
Zoned RSP-1.6-BFC, a single-family residential zone. The parcel point also falls in Undesignated. FEMA Special Flood Hazard Area (Zone AE) covers about 42% 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 RSP-1.6-BFC, a single-family residential zone. The parcel point also falls in Undesignated. The lot is 9,670 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 AE) covers about 42% 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
- Not in a State-mapped fire hazard severity zone
- FEMA National Flood Hazard Layer
- Zone AE: 1% annual chance flood (Special Flood Hazard Area) (about 42% of the lot); Zone X: 0.2% annual chance flood hazard (shaded X) (about 58% of the lot) · FIRM panel 06041C0284E, 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: $1,217,000 – $1,549,000 · Status: Off market
HUD Small Area FMR (ZIP 94949) · FY 2026
Studio $2,360 · 1BR $2,830 · 2BR $3,430 · 3BR $4,380 · 4BR $4,540
Developments Deserving Closer Investigation & Active Area Builders
- Windows / doors / siding (147491) (Issued)On this parcel
Issued after 2 mo — slower than 90% of windows / doors / siding permits in Unincorporated Marin (median 0d, 90th pct 5d, n=1,476).
- Demolition at 18 Dolphin Isle (Issued)480 ft NW
Active in "Issued" for 11.6 yr (first record Mar 25, 2015) with no new permit activity recorded in 11.6 yr.
- Demolition at 1051 Bel Marin Keys Blvd (Issued)0.39 mi N
Active in "Issued" for 8.5 yr (first record May 21, 2018) with no new permit activity recorded in 8.4 yr.
- Accessory dwelling unit at 1108 Bel Marin Keys Blvd (aka 1110) (Issued)0.43 mi NE
Active in "Issued" for 4.6 yr (first record Mar 23, 2022) with no new permit activity recorded in 4.4 yr.
Entity-resolved builders & contractors in ½ mile: Marin Kitchen Works (1 on parcel, 2 in ½ mi · Remodel / interior alteration); Simmitri (2 on parcel, 2 in ½ mi · Roof replacement); Earthwise Energy Solutions (1 on parcel, 1 in ½ mi · Solar / battery storage); Stellar Construction (1 on parcel, 1 in ½ mi · Windows / doors / siding); Owner Builder (21 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B44508 | Solar / battery storage | Issued | Iss. Oct 23, 2025 | $29,222 | 2.46 kW Solar Project including a 15 kWh Battery System |
| 167066 | Remodel / interior alteration | Issued | Iss. Feb 3, 2021 | $30,000 | Mstr Bath Remod - Express |
| 152254 | Solar / battery storage | Issued | Iss. Jun 8, 2016 | $29,782 | 3.597 Kw P V Roof - Express |
| 152249 | Roof replacement | Issued | Iss. Jun 8, 2016 | $8,477 | Reroof |
| 147491 | Windows / doors / siding | Issued | Iss. Jun 10, 2015 | $16,968 |