33 Castle Rock Ave
Woodacre 94973 · Woodacre · Unincorporated Marin · Coordinates: 38.00723, -122.63576
Executive Verdict · Public-Records Synthesis
Zoned R1-B2-SGV-HOD 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 $1,167,000 ($1,027,000–$1,307,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B2-SGV-HOD supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 16,466 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ 9 documented municipal building permits on file
On-parcel permit history is indexed through Jan 23, 2026, 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)
- ! Delayed or open permit activity on this parcel
HVAC / heat pump (91524): Pending in review for 3.1 yr — slower than 90% of hvac / heat pump permits in Unincorporated Marin (median 0d, 90th pct 0d, n=2,946).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 5 slow or stalled nearby projects within ½ mile
Closest lead: New home at 80 Fire Rd (0.37 mi E, 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:
- 16,466 sq ft (0.38 ac)
- Assessor use:
- Tax Exempt
- Addresses on lot:
- 33 CASTLE ROCK AVE
Zoning & Land Use
R1-B2-SGV-HOD — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B2-SGV-HOD (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B2-SGV-HOD, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B2-SGV-HOD, a single-family residential zone. The lot is 16,466 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: $1,027,000 – $1,307,000 · Status: Off market
HUD Small Area FMR (ZIP 94973) · FY 2026
Studio $2,080 · 1BR $2,510 · 2BR $3,020 · 3BR $3,860 · 4BR $4,000
Developments Deserving Closer Investigation & Active Area Builders
- HVAC / heat pump (91524) (Applied)On this parcel
Pending in review for 3.1 yr — slower than 90% of hvac / heat pump permits in Unincorporated Marin (median 0d, 90th pct 0d, n=2,946).
- New home at 80 Fire Rd (Issued)0.37 mi E
Active in "Issued" for 4.1 yr (first record Sep 28, 2022) with no new permit activity recorded in 3.5 yr. High-impact scale (1 housing unit, $2,000,000 declared valuation across 1 permit).
- New home at 15 Edgewood Dr (Applied)0.34 mi SW
In "Applied" for 6.1 yr (since Oct 22, 2020), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Demolition at 90 Carson Rd (Issued)0.29 mi W
Active in "Issued" for 4.8 yr (first record Jan 21, 2022) with no new permit activity recorded in 4.7 yr.
Entity-resolved builders & contractors in ½ mile: Owner Builder (2 on parcel, 10 in ½ mi · New garage / accessory structure); Owner (2 on parcel, 9 in ½ mi · Remodel / interior alteration); Mary Hobson (1 on parcel, 1 in ½ mi · HVAC / heat pump); Henris Supply (1 on parcel, 1 in ½ mi · Roof replacement); Juan Calmell (1 on parcel, 1 in ½ mi · New garage / accessory structure).
Permit & Project History on This Parcel (9 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 180979 | Commercial tenant improvement | Issued | Iss. Jan 23, 2026 | $200,000 | Second Floor Restroom Upgrades; Exterior Accessibility Upgrades. "County Job - County Fire Dept Station" |
| B37642 | Windows / doors / siding | Issued | Iss. May 1, 2024 | $1 | Replace Windows in cupola at Woodacre Fire Shop Building. Cost for this was included in permit # B36153. — Non-structura… |
| B36153 | Roof replacement | Issued | Iss. Nov 20, 2023 | $67,300 | Replace existing asphalt shingle roof. — ReRoofing |
| B35578 | HVAC / heat pump | Issued | Iss. Oct 12, 2023 | $240,000 | Replacement of select HVAC equipment, ductwork and thermostat. Project cost is $83,000 if equipment is not factored in. … |
| 91524 | HVAC / heat pump |