340 Seadrift Rd
Stinson Beach 94970 · Stinson Beach · Unincorporated Marin · Coordinates: 37.90679, -122.67671
Executive Verdict · Public-Records Synthesis
Zoned C-RSPS-2.9 in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA VE flood / Alquist-Priolo fault due diligence; benchmark value $3,377,000 ($2,972,000–$3,782,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone C-RSPS-2.9 allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$202,840 contributory est.)
Public building records show issued construction/renovation work on this parcel (3 total permits, latest May 23, 2023).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (VE, about 84% of the lot of lot)
Zone VE: 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)
- ! Alquist-Priolo Earthquake Fault Zone (all of the lot of lot)
Intersects a State-mapped surface fault rupture zone. Adding habitable structures or subdividing typically requires a site-specific geologic fault investigation.
Source: California Geological Survey Alquist-Priolo Zones
- ! Delayed or open permit activity on this parcel
Remodel / interior alteration (173270): Issued after 11 mo (4.1× the 83d median) — slower than 90% of remodel / interior alteration permits in Unincorporated Marin (median 83d, 90th pct 266d, n=1,054).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 5 slow or stalled nearby projects within ½ mile
Closest lead: New home at 52 Crescente Ave (0.43 mi W, applied). Inspect timeline history before assuming near-term completion.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · HCD APR (½-mile radius)
Parcel & Assessor
- Lot size:
- 15,464 sq ft (0.36 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 340 SEADRIFT RD
Zoning & Land Use
C-RSPS-2.9 — Residential Single Family Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned C-RSPS-2.9 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned C-RSPS-2.9, a single-family residential zone. Alquist-Priolo Earthquake Fault Zone covers all of the lot: the project must meet the seismic building standards, and a fault study is usually required. FEMA Special Flood Hazard Area (Zone VE) covers about 84% 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 C-RSPS-2.9, a single-family residential zone. The lot is 15,464 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original. Alquist-Priolo Earthquake Fault Zone covers all of the lot: the project must meet the seismic building standards, and a fault study is usually required. FEMA Special Flood Hazard Area (Zone VE) covers about 84% 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 VE: 1% annual chance flood (Special Flood Hazard Area) (about 84% of the lot); Zone X: 0.2% annual chance flood hazard (shaded X) (about 16% of the lot) · FIRM panel 06041C0441E, effective August 15, 2017
- CGS Alquist-Priolo Earthquake Fault Zone
- Alquist-Priolo Earthquake Fault Zone (Bolinas quadrangle) (all of the lot)
Surrounding Rent & Value Benchmarks (Public Records)
Range: $2,972,000 – $3,782,000 · Status: Off market
HUD Small Area FMR (ZIP 94970) · FY 2026
Studio $2,090 · 1BR $2,510 · 2BR $3,030 · 3BR $3,870 · 4BR $4,010
Developments Deserving Closer Investigation & Active Area Builders
- New home at 52 Crescente Ave (Applied)0.43 mi W
In "Applied" for 2.3 yr (since Jul 11, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $2,750,000 declared valuation across 1 permit).
- Remodel / interior alteration (173270) (Issued)On this parcel
Issued after 11 mo (4.1× the 83d median) — slower than 90% of remodel / interior alteration permits in Unincorporated Marin (median 83d, 90th pct 266d, n=1,054).
- New home at 342 Seadrift Rd (Issued)80 ft NW
Active in "Issued" for 8 yr (first record Nov 8, 2018) with no new permit activity recorded in 7.8 yr. High-impact scale (1 housing unit, $1,200,000 declared valuation across 1 permit).
- New home at 321 Seadrift Rd (Issued)0.11 mi NE
Active in "Issued" for 3.7 yr (first record Mar 13, 2023) with no new permit activity recorded in 2.8 yr. High-impact scale (1 housing unit, $960,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Kasten Builders (3 on parcel, 5 in ½ mi · New single-family home); Gubbins Building (6 in ½ mi · Remodel / interior alteration); Owner Builder (6 in ½ mi · New single-family home); Peterson Construction And Development (5 in ½ mi · Addition (adds square footage)); Pacific Ridge Construction (4 in ½ mi · Addition (adds square footage)).
Permit & Project History on This Parcel (3 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 174125 | Addition (adds square footage) | Issued | Iss. May 23, 2023 | $100,000 | Detached Addition & Deck, Replacing Structure Demo'd Under P#173270 |
| 174083 | Remodel / interior alteration | Issued | Iss. May 17, 2023 | $10,000 | Kitchen Remodel Outside The Scope Of 173720 |
| 173270 | Remodel / interior alteration | Issued | Iss. Jan 27, 2023 | $1,124,140 | Remodel, Addition, Deck & Stairs, Convert Rec Room To Storage, Windows/Doors, Skylight, Gas Fireplace Insert |