121 Greenbrae Boardwalk
Greenbrae 94904 · Greenbrae · Unincorporated Marin · Coordinates: 37.94169, -122.50938
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 $2,092,000 ($1,841,000–$2,343,000).
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
- ✓ 4 documented municipal building permits on file
On-parcel permit history is indexed through Jul 13, 2022, letting you verify roof, HVAC, electrical, or structural work against seller disclosures.
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
Addition (adds square footage) (76831): Pending in review for 10.7 yr (24.5× the 160d median) — slower than 90% of addition (adds square footage) permits in Unincorporated Marin (median 160d, 90th pct 440d, n=316).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 4 slow or stalled nearby projects within ½ mile
Closest lead: New home (0.17 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 (~$24,508/yr at $2,092,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,042/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:
- 7,318 sq ft (0.17 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 121 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 7,318 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: $1,841,000 – $2,343,000 · 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
- Addition (adds square footage) (76831) (Applied)On this parcel
Pending in review for 10.7 yr (24.5× the 160d median) — slower than 90% of addition (adds square footage) permits in Unincorporated Marin (median 160d, 90th pct 440d, n=316).
- New home (Entitled)0.17 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).
- General repair (171900) (Issued)On this parcel
Issued after 10 mo (3.5× the 83d median) — above the 75th percentile for general repair permits in Unincorporated Marin (median 83d, 75th pct 181d, n=693).
- New home at 193 Sir Francis Drake Blvd E (Applied)0.23 mi N
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).
Entity-resolved builders & contractors in ½ mile: Bachelder And Associates (1 on parcel, 1 in ½ mi · General repair); Safe And Warm Chimney Service (1 on parcel, 1 in ½ mi · HVAC / heat pump); Beckmann Construction (1 on parcel, 1 in ½ mi · Windows / doors / siding); Owner Builder (7 in ½ mi · Demolition); Owner (2 in ½ mi · Addition (adds square footage)).
Permit & Project History on This Parcel (4 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 171900 | General repair | Issued | Iss. Jul 13, 2022 | $346,299 | Raise House And Deck Above B F E- *Structural Elevation Project* |
| 76831 | Addition (adds square footage) | Applied | App. Feb 17, 2016 | $63,750 | Studio Addn; Repl Deck Plans Tossed 12/5/18 |
| 149197 | Windows / doors / siding | Issued | Iss. Oct 1, 2015 | $3,000 | Window Replacement Like For Like To Meet Fenestration |
| 144405 | HVAC / heat pump | Issued | Iss. Oct 6, 2014 | $3,860 | Install Gas Firepl Where Woodburner Used To Be |