328 Montford Ave
Mill Valley 94941 · Homestead · Unincorporated Marin · Coordinates: 37.89789, -122.54534
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 $2,242,000 ($1,973,000–$2,511,000).
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 8,712 sq ft lot. Local precedent is active with 4 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$51,600 contributory est.)
Public building records show issued construction/renovation work on this parcel (6 total permits, latest Jul 13, 2023).
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 22% 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 garage / accessory structure (91315): Pending in review for 3.3 yr (7.4× the 164d median) — slower than 90% of new garage / accessory structure permits in Unincorporated Marin (median 164d, 90th pct 485d, n=356).
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: Accessory dwelling unit at 408 Laverne Ave (adu 408a) (0.21 mi W, 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:
- 8,712 sq ft (0.20 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 328 MONTFORD 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 8,712 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 22% of the lot, map Apr 1, 2024); Moderate Fire Hazard Severity Zone (State Responsibility Area) (about 78% 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: $1,973,000 – $2,511,000 · 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 garage / accessory structure (91315) (Applied)On this parcel
Pending in review for 3.3 yr (7.4× the 164d median) — slower than 90% of new garage / accessory structure permits in Unincorporated Marin (median 164d, 90th pct 485d, n=356).
- Accessory dwelling unit at 408 Laverne Ave (adu 408a) (Issued)0.21 mi W
Active in "Issued" for 2.3 yr (first record Jul 12, 2024) with no new permit activity recorded in 14 mo. High-impact scale (1 housing unit, $2,700,000 declared valuation across 1 permit).
- New home at 420 Laverne Ave (Issued)0.24 mi W
Active in "Issued" for 8.6 yr (first record Apr 23, 2018) with no new permit activity recorded in 3.8 yr. High-impact scale (1 housing unit, $1,100,000 declared valuation across 1 permit).
- New home at 107 Montford Ave (Issued)0.24 mi E
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: American Solar (2 on parcel, 2 in ½ mi · Solar / battery storage); Homage Building (1 on parcel, 1 in ½ mi · Remodel / interior alteration); John Owens Services (1 on parcel, 1 in ½ mi · HVAC / heat pump); Northern Pacific Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Owner Builder (43 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (6 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 91315 | New garage / accessory structure | Applied | App. Jul 13, 2023 | $75,000 | Replace (E) Front Overhang W/ Pergola & Deck |
| B34675 | Solar / battery storage | Issued | Iss. Jul 11, 2023 | $16,000 | 28kWh Battery ESS installation ((2) Tesla AC Powerwall 2.0) & outlet circuit installation. |
| B27155 | Roof replacement | Issued | Iss. Sep 24, 2021 | $15,000 | Remove and Replace Class A shingles — ReRoofing; With Electronic Inspection |
| B26965 | Solar / battery storage | Issued | Iss. Sep 13, 2021 | $26,000 | 6.08kW PV Array w/ Inverter & MSP Upgrade |
| B25344 | HVAC / heat pump | Issued | Iss. Apr 2, 2021 |