31 Mt Muir Ct
San Rafael 94903 · Lucas Valley · Unincorporated Marin · Coordinates: 38.02749, -122.57323
Executive Verdict · Public-Records Synthesis
Zoned R1-B-LV in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AE flood / CAL FIRE high fire hazard severity zone (local responsibility area) due diligence; benchmark value $1,389,000 ($1,222,000–$1,556,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone R1-B-LV allows residential use qualifying for ministerial ADU review under state law (1 ADU permit permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ 2 documented municipal building permits on file
On-parcel permit history is indexed through Nov 24, 2021, 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
- ! FEMA Special Flood Hazard Area (AE, about 42% of the lot of lot)
Zone AE: 1% annual chance flood (Special Flood Hazard Area) overlaps this parcel. Expect mandatory flood insurance for federally backed loans and floodplain elevation/mitigation rules for new units or SB 9 applications.
Source: FEMA National Flood Hazard Layer (parcel polygon)
- ! CAL FIRE High 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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home (0.31 mi E, 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 (~$16,424/yr at $1,389,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,369/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:
- 8,712 sq ft (0.20 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 31 MT MUIR CT
Zoning & Land Use
R1-B-LV — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B-LV (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned R1-B-LV, a single-family residential zone. FEMA Special Flood Hazard Area (Zone AE) covers about 42% of the lot: the project must meet the National Flood Insurance Program floodplain standards, or the lot needs a map revision.
- SB 9: split into two lotsPossible, with conditions
Zoned R1-B-LV, 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. FEMA Special Flood Hazard Area (Zone AE) covers about 42% of the lot: the project must meet the National Flood Insurance Program floodplain standards, or the lot needs a map revision.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- High Fire Hazard Severity Zone (Local Responsibility Area) (all of the lot, map Mar 24, 2025)
- FEMA National Flood Hazard Layer
- Zone AE: 1% annual chance flood (Special Flood Hazard Area) (about 42% of the lot); Zone X: minimal flood hazard (about 58% of the lot) · FIRM panel 06041C0289D, 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: $1,222,000 – $1,556,000 · Status: Off market
HUD Small Area FMR (ZIP 94903) · FY 2026
Studio $2,880 · 1BR $3,450 · 2BR $4,180 · 3BR $5,340 · 4BR $5,530
Developments Deserving Closer Investigation & Active Area Builders
- New home (Entitled)0.31 mi E
In "Entitled" for 2.9 yr (since Dec 7, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home (Entitled)0.31 mi E
In "Entitled" for 3.3 yr (since Jul 10, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home (Entitled)0.31 mi E
In "Entitled" for 3.8 yr (since Jan 14, 2023), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home (Entitled)0.31 mi E
In "Entitled" for 5.1 yr (since Sep 23, 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: Capstone Roofing (1 on parcel, 1 in ½ mi · Roof replacement); 101 Plumbing Heating And Cooling (1 on parcel, 1 in ½ mi · HVAC / heat pump); Owner Builder (21 in ½ mi · Remodel / interior alteration); Tim Lawlor Construction (6 in ½ mi · Remodel / interior alteration); Marin Kitchen Works (5 in ½ mi · Addition (adds square footage)).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B27889 | HVAC / heat pump | Issued | Iss. Nov 24, 2021 | $3,500 | Gas Furnace replacement — Replace Mechanical Appliance |
| B27737 | Roof replacement | Issued | Iss. Nov 15, 2021 | $20,600 | Reroof-Replace with Comp Class A shingles; 39sqs-Self Certify — ReRoofing |