150 Main Dr
San Rafael 94901 · Bayside Acres · Unincorporated Marin · Coordinates: 37.98319, -122.48198
Executive Verdict · Public-Records Synthesis
Zoned R1-B4 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (local responsibility area) due diligence; benchmark value $1,739,000 ($1,530,000–$1,948,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B4 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 32,278 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$27,080 contributory est.)
Public building records show issued construction/renovation work on this parcel (8 total permits, latest Jan 6, 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 (Local 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 Mar 24, 2025)
- ! Delayed or open permit activity on this parcel
New garage / accessory structure (80297): Pending in review for 9.4 yr (20.9× 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)
- ! 4 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)
Parcel & Assessor
- Lot size:
- 32,278 sq ft (0.74 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 150 MAIN DR
Zoning & Land Use
R1-B4 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B4 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B4, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B4, a single-family residential zone. The lot is 32,278 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 (Local Responsibility Area) (all of the lot, map Mar 24, 2025)
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06041C0476E, 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: $1,530,000 – $1,948,000 · Status: Off market
HUD Small Area FMR (ZIP 94901) · FY 2026
Studio $2,150 · 1BR $2,580 · 2BR $3,120 · 3BR $3,990 · 4BR $4,130
Developments Deserving Closer Investigation & Active Area Builders
- New garage / accessory structure (80297) (Applied)On this parcel
Pending in review for 9.4 yr (20.9× the 164d median) — slower than 90% of new garage / accessory structure permits in Unincorporated Marin (median 164d, 90th pct 485d, n=356).
- New home (Entitled)0.27 mi N
In "Entitled" for 7.8 yr (since Jan 14, 2019), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New garage / accessory structure (93902) (Applied)On this parcel
Pending in review for 10 mo (1.9× the 164d median) — above the 75th percentile for new garage / accessory structure permits in Unincorporated Marin (median 164d, 75th pct 294d, n=356).
- New home (Entitled)0.43 mi NE
In "Entitled" for 5.3 yr (since Jul 12, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Entity-resolved builders & contractors in ½ mile: Owner (2 on parcel, 6 in ½ mi · Remodel / interior alteration); Hendrickson Pools (2 on parcel, 2 in ½ mi · New garage / accessory structure); D2 Construction (1 on parcel, 1 in ½ mi · New garage / accessory structure); Owner Builder (7 in ½ mi · Remodel / interior alteration); Dream Home Building (2 in ½ mi · New garage / accessory structure).
Permit & Project History on This Parcel (8 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 93902 | New garage / accessory structure | Applied | App. Jan 6, 2026 | $320,000 | (N) Addition To Sfd And (N) Garage. |
| 166091 | Solar / battery storage | Issued | Iss. Oct 29, 2020 | $14,000 | Energy Storage System -Bbw |
| 162723 | New garage / accessory structure | Issued | Iss. Sep 23, 2019 | $600,000 | Addn; Rmdl, Rbld Eext Closet; Ret Wall T.D. 6/7/19 |
| B12886 | Electrical / panel | Issued | Iss. Jul 25, 2017 | $500 | Upgrade electrical panel — Service Upgrade |
| 80297 | New garage / accessory structure | Applied | App. Jun 20, 2017 | $600,000 |