109 Greenbrae Boardwalk
Greenbrae 94904 · Greenbrae · Unincorporated Marin · Coordinates: 37.94164, -122.51019
Executive Verdict · Public-Records Synthesis
Zoned RSP-4.36-BFC in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AE flood due diligence; benchmark value $2,022,000 ($1,779,000–$2,265,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RSP-4.36-BFC allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$11,350 contributory est.)
Public building records show issued construction/renovation work on this parcel (6 total permits, latest Feb 10, 2021).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (AE, all 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
Electrical / panel (150953): Issued after 2.1 yr — slower than 90% of electrical / panel permits in Unincorporated Marin (median 0d, 90th pct 2d, n=3,019).
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: New home (0.13 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 (~$23,703/yr at $2,022,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,975/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:
- 4,443 sq ft (0.10 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 109 GREENBRAE BOARDWALK
Zoning & Land Use
RSP-4.36-BFC — Residential Single Family Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RSP-4.36-BFC (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned RSP-4.36-BFC, a single-family residential zone. FEMA Special Flood Hazard Area (Zone AE) covers all 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-4.36-BFC, a single-family residential zone. The lot is 4,443 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 all 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) (all of the lot) · FIRM panel 06041C0459F, 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: $1,779,000 – $2,265,000 · Status: Off market
HUD Small Area FMR (ZIP 94904) · FY 2026
Studio $2,260 · 1BR $2,710 · 2BR $3,280 · 3BR $4,190 · 4BR $4,340
Developments Deserving Closer Investigation & Active Area Builders
- Electrical / panel (150953) (Issued)On this parcel
Issued after 2.1 yr — slower than 90% of electrical / panel permits in Unincorporated Marin (median 0d, 90th pct 2d, n=3,019).
- New home (Entitled)0.13 mi W
In "Entitled" for 5.1 yr (since Oct 1, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home at 193 Sir Francis Drake Blvd E (Applied)0.25 mi NE
Active in "Applied" for 14 mo (first record Aug 29, 2025) with no new permit activity recorded in 10 mo. High-impact scale ($109,000,000 declared valuation across 2 permits).
- Demolition at 113 Greenbrae Boardwalk (Issued)70 ft E
Active in "Issued" for 12.6 yr (first record Apr 23, 2014) with no new permit activity recorded in 12.5 yr.
Entity-resolved builders & contractors in ½ mile: Owner (3 on parcel, 5 in ½ mi · Addition (adds square footage)); Enstad Construction (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Tesla Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Earth Star Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (7 in ½ mi · Demolition).
Permit & Project History on This Parcel (6 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B24825 | Electrical / panel | Issued | Iss. Feb 10, 2021 | $5,300 | Electrical service upgrade (replacement) 200A. Main panel will be relocated from front of house to the west side of hous… |
| 166956 | Solar / battery storage | Issued | Iss. Jan 26, 2021 | $13,040 | 4.08kw Rooftop Photovoltaic & Energy Storage System |
| B23214 | Windows / doors / siding | Issued | Iss. Aug 11, 2020 | $3,500 | Replacing three windows — Non-structural Door/Window Replacement |
| 150954 | Remodel / interior alteration | Issued | Iss. Feb 29, 2016 | $15,000 | Bath Remodel T.D. 2/10/16 |
| 150953 | Electrical / panel | Issued | Iss. Feb 29, 2016 |