596 Ethel Ave
Mill Valley 94941 · Homestead · Unincorporated Marin · Coordinates: 37.89512, -122.53715
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AE flood / CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,241,000 ($1,972,000–$2,510,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone R1-B1 allows residential use qualifying for ministerial ADU review under state law (5 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ 3 documented municipal building permits on file
On-parcel permit history is indexed through Sep 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)
- ✓ Above-average reinvestment in Homestead
22 substantial renovation & housing permits over 24 months (20.7 per 1,000 parcels vs. 16.4 citywide baseline) (#2 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Homestead)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (AE, about 99% of the lot of lot)
Zone AE: regulatory floodway (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)
- ! CAL FIRE Moderate Fire Hazard Severity Zone (State Responsibility Area) (all of the lot of lot)
Located in a mapped Fire Hazard Severity Zone. Expect Chapter 7A ignition-resistant building standards, defensible-space inspections, and stricter property insurance underwriting.
Source: CAL FIRE FHSZ (map Apr 1, 2024)
- ! Delayed or open permit activity on this parcel
New home at 596 Ethel Ave: Active in "Issued" for 10.7 yr (first record Feb 24, 2016) with no new permit activity recorded in 10.5 yr. High-impact scale (1 housing unit, $1,100,000 declared valuation across 1 permit).
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 at 204 Reed St (0.23 mi SW, 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)
Parcel & Assessor
- Lot size:
- 11,718 sq ft (0.27 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 596 ETHEL AVE
Zoning & Land Use
R1-B1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned R1-B1, a single-family residential zone. FEMA regulatory floodway covers about 99% of the lot: SB 9 requires a no-rise certification.
- SB 9: split into two lotsPossible, with conditions
Zoned R1-B1, a single-family residential zone. The lot is 11,718 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original. FEMA regulatory floodway covers about 99% of the lot: SB 9 requires a no-rise certification.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Moderate Fire Hazard Severity Zone (State Responsibility Area) (all of the lot, map Apr 1, 2024)
- FEMA National Flood Hazard Layer
- Zone AE: regulatory floodway (Special Flood Hazard Area) (about 99% of the lot); Zone AE: 1% annual chance flood (Special Flood Hazard Area) (about 1% of the lot) · FIRM panel 06041C0468F, 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: $1,972,000 – $2,510,000 · Status: Off market
HUD Small Area FMR (ZIP 94941) · FY 2026
Studio $2,730 · 1BR $3,270 · 2BR $3,960 · 3BR $5,060 · 4BR $5,240
Developments Deserving Closer Investigation & Active Area Builders
- New home at 596 Ethel Ave (Issued)On this parcel
Active in "Issued" for 10.7 yr (first record Feb 24, 2016) with no new permit activity recorded in 10.5 yr. High-impact scale (1 housing unit, $1,100,000 declared valuation across 1 permit).
- Plumbing / water heater / sewer (90307) (Applied)On this parcel
Pending in review for 4.2 yr — slower than 90% of plumbing / water heater / sewer permits in Unincorporated Marin (median 0d, 90th pct 0d, n=2,211).
- New home at 204 Reed St (Issued)0.23 mi SW
Active in "Issued" for 4.3 yr (first record Aug 5, 2022) with no new permit activity recorded in 3.5 yr. High-impact scale (1 housing unit, $950,000 declared valuation across 1 permit).
- New home at 107 Montford Ave (Issued)0.25 mi NW
Active in "Issued" for 3.9 yr (first record Dec 15, 2022) with no new permit activity recorded in 2.5 yr. High-impact scale (1 housing unit, $1,375,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: True Blue Builders (1 on parcel, 1 in ½ mi · New single-family home); Acco Electrical (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (60 in ½ mi · Remodel / interior alteration); Owner (27 in ½ mi · Remodel / interior alteration); Tamalpais Construction (6 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (3 permits, 1 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 90307 | Plumbing / water heater / sewer | Applied | App. Sep 13, 2022 | $45,000 | Deck; Portable Spa, Portable Gas Fire Pit, & Outdoor Bar T.D. 10-3-22 |
| 151993 | New single-family home | Issued | Iss. May 16, 2016 | $1,100,000 | Sfd - Demo & Rebuild. Change Contr 7/18/16 True Blue Builders |
| 151879 | Electrical / panel | Issued | Iss. May 5, 2016 | $150 | Temp Power Pole |