30 Rosario Rd
Forest Knolls 94933 · Forest Knolls · Unincorporated Marin · Coordinates: 38.01100, -122.68699
Executive Verdict · Public-Records Synthesis
Zoned R1-B3-SGV 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 $898,000 ($790,000–$1,006,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B3-SGV supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 7,057 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ 2 documented municipal building permits on file
On-parcel permit history is indexed through May 29, 2025, letting you verify roof, HVAC, electrical, or structural work against seller disclosures.
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 High 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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home at 110 Rosario Rd (360 ft SW, 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)
- ! Year 1 Prop 13 tax reset (~$10,777/yr at $898,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$898/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:
- 7,057 sq ft (0.16 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 30 ROSARIO RD
Zoning & Land Use
R1-B3-SGV — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B3-SGV (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B3-SGV, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B3-SGV, a single-family residential zone. The lot is 7,057 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) (all of the lot, map Apr 1, 2024)
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06041C0275D, effective May 4, 2009
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $790,000 – $1,006,000 · Status: Off market
HUD Small Area FMR (ZIP 94933) · FY 2026
Studio $2,870 · 1BR $3,440 · 2BR $4,160 · 3BR $5,310 · 4BR $5,510
Developments Deserving Closer Investigation & Active Area Builders
- New home at 110 Rosario Rd (Issued)360 ft SW
Active in "Issued" for 12.5 yr (first record May 29, 2014) with no new permit activity recorded in 11.5 yr.
- Demolition at 51 Aztec Ave (aka Lower Aztec) (Issued)0.11 mi N
Active in "Issued" for 11.9 yr (first record Dec 10, 2014) with no new permit activity recorded in 11.9 yr.
- New home at 350 Montezuma Ave (Issued)0.17 mi SE
Active in "Issued" for 4.7 yr (first record Feb 25, 2022) with no new permit activity recorded in 17 mo.
- Demolition at 395 Montezuma Ave (Issued)0.22 mi SE
Active in "Issued" for 10.7 yr (first record Feb 17, 2016) with no new permit activity recorded in 10.7 yr.
Entity-resolved builders & contractors in ½ mile: Owner (1 on parcel, 9 in ½ mi · New single-family home); Hennessey Construction (1 on parcel, 1 in ½ mi · Windows / doors / siding); Owner Builder (11 in ½ mi · Demolition); Zia Designs (2 in ½ mi · Demolition); Rebuilding Together East Bay Network (1 in ½ mi · Accessory dwelling unit (new or conversion)).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B42581 | Windows / doors / siding | Issued | Iss. May 29, 2025 | $25,000 | Re-glaze fixed windows #1 - #5 Replace #6 and #7. — Non-structural Door/Window Replacement |
| B17753 | Other | Issued | Iss. May 12, 2019 | $2,500 | Install propane heating appliance to replace wood stove — Mechanical Appliance |