210 A Hawthorne Ave
Mill Valley 94941 · Homestead · Unincorporated Marin · Coordinates: 37.89488, -122.54066
Executive Verdict · Public-Records Synthesis
Zoned R1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,317,000 ($2,039,000–$2,595,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 4,225 sq ft lot. Local precedent is active with 5 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$249,550 contributory est.)
Public building records show issued construction/renovation work on this parcel (3 total permits, latest Apr 29, 2024).
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
- ! Mapped flood awareness zone (Zone X: minimal flood hazard)
all of the lot of the parcel intersects Zone X: minimal flood hazard. Outside mandatory federal SFHA insurance rules, but check local drainage and finished-floor requirements.
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
Accessory dwelling unit (new or conversion) (176510): Issued after 16 mo (2.4× the 204d median) — above the 75th percentile for accessory dwelling unit (new or conversion) permits in Unincorporated Marin (median 204d, 75th pct 331d, n=298).
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 204 Reed St (490 ft S, 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:
- 4,225 sq ft (0.10 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 210A HAWTHORNE AVE; 210 HAWTHORNE AVE
Zoning & Land Use
R1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1, a single-family residential zone. The lot is 4,225 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original.
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 X: minimal flood hazard (all 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: $2,039,000 – $2,595,000 · 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 204 Reed St (Issued)490 ft S
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 210 Brabo Ter (Issued)0.12 mi S
Active in "Issued" for 3.1 yr (first record Oct 12, 2023) with no new permit activity recorded in 2.6 yr. High-impact scale (1 housing unit, $850,000 declared valuation across 1 permit).
- New home at 107 Montford Ave (Issued)0.13 mi N
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).
- 9 new homes (Issued)0.4 mi E
Active in "Issued" for 5.4 yr (first record Jun 9, 2021) with no new permit activity recorded in 5.4 yr. High-impact scale (9 housing units across 0 permits).
Entity-resolved builders & contractors in ½ mile: Structural Integrity (1 on parcel, 1 in ½ mi · Accessory dwelling unit (new or conversion)); Semper Solaris (1 on parcel, 1 in ½ mi · Solar / battery storage); Ernest Ongaro And Sons (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Owner Builder (70 in ½ mi · Remodel / interior alteration); Owner (33 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (3 permits, 1 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 176510 | Accessory dwelling unit (new or conversion) | Issued | Iss. Apr 29, 2024 | $378,900 | A D U At [N] Upper Floor; Decks |
| 168360 | Solar / battery storage | Issued | Iss. Jun 4, 2021 | $28,750 | Energy Storage System - Express |
| B14199 | Plumbing / water heater / sewer | Issued | Iss. Jan 29, 2018 | $2,100 | Replace all gas lines under home. — New Gas Service, Replace Plumbing Fixtures(s) |
State HCD Housing Element APR records on this parcel: 4 entries (report years 2023, 2024, 2025).