100 W Oak Knoll Dr
San Anselmo 94960 · Sleepy Hollow · Unincorporated Marin · Coordinates: 38.00094, -122.58460
Executive Verdict · Public-Records Synthesis
Zoned RMP-0.2 in Unincorporated Marin with likely ministerial ADU eligibility and mapped CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $1,811,000 ($1,594,000–$2,028,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-0.2 allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$19,407 contributory est.)
Public building records show issued construction/renovation work on this parcel (7 total permits, latest May 10, 2026).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Sleepy Hollow
32 substantial renovation & housing permits over 24 months (32.7 per 1,000 parcels vs. 16.4 citywide baseline) (#4 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Sleepy Hollow)
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 (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 40 De Burgh Dr (0.42 mi N, 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)
- ! Year 1 Prop 13 tax reset (~$21,277/yr at $1,811,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,773/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:
- 230,650 sq ft (5.29 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 100 W OAK KNOLL DR
Zoning & Land Use
RMP-0.2 — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-0.2 (multifamily residential): state law allows ADUs where homes are allowed. On a multifamily lot the state allowance is different: ADUs in non-living space of the building, plus up to eight detached ADUs.
- SB 9: two homes on the lotUnlikely
Zoned RMP-0.2 (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-0.2 (multifamily residential), not a single-family residential zone.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Moderate 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 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: $1,594,000 – $2,028,000 · Status: Off market
HUD Small Area FMR (ZIP 94960) · FY 2026
Studio $2,510 · 1BR $3,010 · 2BR $3,640 · 3BR $4,650 · 4BR $4,820
Developments Deserving Closer Investigation & Active Area Builders
- New home at 40 De Burgh Dr (Applied)0.42 mi N
In "Applied" for 9.3 yr (since Jul 31, 2017), 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, $1,800,000 declared valuation across 3 permits).
- New home at 71 W Oak Knoll Dr (Applied)380 ft NE
In "Applied" for 5.2 yr (since Sep 1, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- 135 Woodside, Unit A (Entitled)0.24 mi S
In "Entitled" for 8.2 yr (since Sep 7, 2018), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home (Issued)0.28 mi SE
Active in "Issued" for 14 mo (first record Sep 2, 2025) with no new permit activity recorded in 14 mo.
Entity-resolved builders & contractors in ½ mile: Summit Professional Builders (2 on parcel, 2 in ½ mi · New garage / accessory structure); Russell Electric (1 on parcel, 1 in ½ mi · Solar / battery storage); Charles Window And Door (1 on parcel, 1 in ½ mi · Windows / doors / siding); Stroub Construction (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Bellows Plumbing Heating And Air (1 on parcel, 1 in ½ mi · Other).
Permit & Project History on This Parcel (7 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B46754 | Other | Issued | Iss. May 10, 2026 | $12,000 | Replace Mechanical Appliance |
| B41460 | Plumbing / water heater / sewer | Issued | Iss. Mar 3, 2025 | $16,577 | Install generator including natural gas line and electrical connections. |
| 167113 | Solar / battery storage | Issued | Iss. Feb 9, 2021 | $30,686 | 13.940kw Rooftop Photovoltaic |
| 165808 | New garage / accessory structure | Issued | Iss. Sep 23, 2020 | $758,520 | Remod, Addtn, Deck, Porch T.D. 6-5-20 |
| 163801 | Remodel / interior alteration | Issued | Iss. Jan 2, 2020 | $20,000 |