45 A Bosque Ave
Fairfax 94930 · Unincorporated Fairfax · Unincorporated Marin · Coordinates: 37.97208, -122.61295
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 $1,846,000 ($1,624,000–$2,068,000).
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 15,769 sq ft lot. Local precedent is active with 1 ADU permit within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$494,282 contributory est.)
Public building records show issued construction/renovation work on this parcel (6 total permits, latest May 5, 2026).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
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) (181594): Issued after 21 mo (3.2× the 204d median) — slower than 90% of accessory dwelling unit (new or conversion) permits in Unincorporated Marin (median 204d, 90th pct 549d, n=298).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 3 slow or stalled nearby projects within ½ mile
Closest lead: Demolition at 2 Mora Ave (0.13 mi NW, 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:
- 15,769 sq ft (0.36 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 45A BOSQUE AVE; 45 BOSQUE 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 15,769 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 06041C0451E, effective March 17, 2014
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $1,624,000 – $2,068,000 · Status: Off market
HUD Small Area FMR (ZIP 94930) · FY 2026
Studio $2,230 · 1BR $2,680 · 2BR $3,240 · 3BR $4,140 · 4BR $4,290
Developments Deserving Closer Investigation & Active Area Builders
- Accessory dwelling unit (new or conversion) (181594) (Issued)On this parcel
Issued after 21 mo (3.2× the 204d median) — slower than 90% of accessory dwelling unit (new or conversion) permits in Unincorporated Marin (median 204d, 90th pct 549d, n=298).
- Addition (adds square footage) (181593) (Issued)On this parcel
Issued after 22 mo (4.1× the 160d median) — slower than 90% of addition (adds square footage) permits in Unincorporated Marin (median 160d, 90th pct 440d, n=316).
- Accessory dwelling unit at 45 Bosque Ave (Issued)On this parcel
Active in "Issued" for 2.3 yr (first record Jul 31, 2024) with no new permit activity recorded in 6 mo.
- Demolition at 2 Mora Ave (Issued)0.13 mi NW
Active in "Issued" for 4.6 yr (first record Apr 26, 2022) with no new permit activity recorded in 4.5 yr.
Entity-resolved builders & contractors in ½ mile: Morgan Key Hammon Construction (2 on parcel, 2 in ½ mi · Accessory dwelling unit (new or conversion)); Simply Solar (1 on parcel, 1 in ½ mi · Solar / battery storage); Moore Home Services (1 on parcel, 1 in ½ mi · HVAC / heat pump); Tesla Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Moore Services (1 on parcel, 1 in ½ mi · HVAC / heat pump).
Permit & Project History on This Parcel (6 permits, 1 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 181594 | Accessory dwelling unit (new or conversion) | Issued | Iss. May 5, 2026 | $560,000 | New Det A D U; Decks; Ret Walls; Spa |
| 181593 | Addition (adds square footage) | Issued | Iss. May 5, 2026 | $300,000 | Addition: Office @ Lower Lvl & Closet @ Upper Lvl; Decks; Outdoor Kitchen |
| B30325 | HVAC / heat pump | Issued | Iss. Jul 11, 2022 | $18,000 | INSTALL NEW 3.5 TON 18 SEER 2 HEAD MINI SPLIT SYSTEM ON LEFT SIDE YARD. — Mechanical Appliance |
| B22033 | HVAC / heat pump | Issued | Iss. Feb 10, 2020 | $9,500 |