47 Ridge Ave
Mill Valley 94941 · Muir Woods Park · Unincorporated Marin · Coordinates: 37.89817, -122.56555
Executive Verdict · Public-Records Synthesis
Zoned R1-B4 in Unincorporated Marin and mapped CAL FIRE very high fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,285,000 ($2,011,000–$2,559,000).
Upsides & Opportunities
- ✓ 14 documented municipal building permits on file
On-parcel permit history is indexed through Aug 5, 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
- ! Mapped flood awareness zone (Zone D: possible but undetermined flood hazard)
all of the lot of the parcel intersects Zone D: possible but undetermined 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 Very 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)
- ! Delayed or open permit activity on this parcel
Demolition (75334): Pending in review for 11.2 yr (74.3× the 55d median) — slower than 90% of demolition permits in Unincorporated Marin (median 55d, 90th pct 261d, n=130).
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 at 65 Ridge Ave (420 ft SE, applied). 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:
- 57,935 sq ft (1.33 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 47 RIDGE AVE
Zoning & Land Use
R1-B4 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADUPossible, with conditions
Zoned R1-B4 (single-family residential): state law allows ADUs where homes are allowed. Very High Fire Hazard Severity Zone covers all of the lot: cities may limit ADUs here for fire safety and evacuation.
- SB 9: two homes on the lotPossible, with conditions
Zoned R1-B4, a single-family residential zone. Very High Fire Hazard Severity Zone (State responsibility area) covers all of the lot: SB 9 requires the project to meet the fire hazard mitigation standards.
- SB 9: split into two lotsPossible, with conditions
Zoned R1-B4, a single-family residential zone. The lot is 57,935 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original. Very High Fire Hazard Severity Zone (State responsibility area) covers all of the lot: SB 9 requires the project to meet the fire hazard mitigation standards.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Very High Fire Hazard Severity Zone (State Responsibility Area) (all of the lot, map Apr 1, 2024)
- FEMA National Flood Hazard Layer
- Zone D: possible but undetermined flood hazard (all of the lot) · FIRM panel 06041C0465E, effective August 15, 2017
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $2,011,000 – $2,559,000 · 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 home at 65 Ridge Ave (Applied)420 ft SE
In "Applied" for 4 yr (since Oct 27, 2022), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $3,000,000 declared valuation across 1 permit).
- Demolition (75334) (Applied)On this parcel
Pending in review for 11.2 yr (74.3× the 55d median) — slower than 90% of demolition permits in Unincorporated Marin (median 55d, 90th pct 261d, n=130).
- New home at 526 Panoramic Hwy (Issued)0.29 mi NW
Active in "Issued" for 4.6 yr (first record Apr 21, 2022) with no new permit activity recorded in 2.1 yr. High-impact scale (1 housing unit, $1,329,450 declared valuation across 2 permits).
- New home at 49 Ridge Ave (Applied)210 ft W
In "Applied" for 5.1 yr (since Oct 15, 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 Builder (2 on parcel, 29 in ½ mi · Remodel / interior alteration); Northbay Home Construction Solutions (2 on parcel, 2 in ½ mi · General repair); Jemico (2 on parcel, 2 in ½ mi · Windows / doors / siding); Portico Builders (1 on parcel, 1 in ½ mi · Other); Haddon Heating And Cooling (1 on parcel, 1 in ½ mi · HVAC / heat pump).
Permit & Project History on This Parcel (14 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 169017 | General repair | Issued | Iss. Aug 5, 2021 | $74,000 | Repl Deck Flooring,And Railings |
| B26419 | Windows / doors / siding | Issued | Iss. Jul 27, 2021 | $3,500 | Remove and install 3 new windows — Siding Replacement, Non-structural Door/Window Replacement |
| B25832 | Roof replacement | Issued | Iss. May 24, 2021 | $9,700 | remove existing composition shingles install 30 yr class A composition shingles 15lbs water block underlayment new flash… |
| B24608 | Plumbing / water heater / sewer | Issued | Iss. Jan 12, 2021 | $1,800 | Replace two failed 50 gal water heaters with two new 50 gal water heaters — New Gas Service, Replace Plumbing Fixtures(s… |
| B23356 | HVAC / heat pump |