309 Holly St
Mill Valley 94941 · Homestead · Unincorporated Marin · Coordinates: 37.89697, -122.54533
Executive Verdict · Public-Records Synthesis
Zoned R1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,186,000 ($1,924,000–$2,448,000).
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 7,623 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 (+$18,176 contributory est.)
Public building records show issued construction/renovation work on this parcel (3 total permits, latest May 27, 2022).
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 High Fire Hazard Severity Zone (State Responsibility Area) (about 48% 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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home (0.27 mi N, 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 (~$25,589/yr at $2,186,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,132/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:
- 7,623 sq ft (0.17 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 309 HOLLY ST
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 7,623 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
- High Fire Hazard Severity Zone (State Responsibility Area) (about 48% of the lot, map Apr 1, 2024); Moderate Fire Hazard Severity Zone (State Responsibility Area) (about 52% 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: $1,924,000 – $2,448,000 · 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 (Entitled)0.27 mi N
In "Entitled" for 6.4 yr (since Jun 23, 2020), 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, 1 deed-restricted affordable across 0 permits).
- New home (Entitled)0.29 mi NW
In "Entitled" for 6.3 yr (since Aug 11, 2020), 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, 1 deed-restricted affordable across 0 permits).
- New home at 306 Holly St (Issued)120 ft W
Active in "Issued" for 8.1 yr (first record Sep 19, 2018) with no new permit activity recorded in 7.6 yr. High-impact scale (1 housing unit, $870,000 declared valuation across 1 permit).
- New commercial building at 305 Montford Ave (Issued)0.11 mi E
Active in "Issued" for 7.5 yr (first record May 13, 2019) with no new permit activity recorded in 7.2 yr. High-impact scale ($2,600,000 declared valuation across 2 permits).
Entity-resolved builders & contractors in ½ mile: Dry Tech Roofing (1 on parcel, 1 in ½ mi · Roof replacement); American Solar (1 on parcel, 1 in ½ mi · Solar / battery storage); Tesla Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Owner Builder (47 in ½ mi · Remodel / interior alteration); Owner (21 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (3 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B29883 | Solar / battery storage | Issued | Iss. May 27, 2022 | $32,000 | 10.79kW PV Array w/ 14kWh addition to existing Battery ESS, MSP change-out/upgrade |
| B28766 | Roof replacement | Issued | Iss. Feb 17, 2022 | $51,675 | 1. Apply High Temperature Poly Moisture Barrier over roof decking. A. Remove existing roofing as needed. B. Replacement … |
| 166237 | Solar / battery storage | Issued | Iss. Nov 12, 2020 | $1,400 | Energy Storage System |