40 Garden Rock Rd
San Anselmo 94960 · Sleepy Hollow · Unincorporated Marin · Coordinates: 38.01482, -122.59083
Executive Verdict · Public-Records Synthesis
Zoned R1-BD in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $1,920,000 ($1,690,000–$2,150,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-BD supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 14,680 sq ft lot. Local precedent is active with 3 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ 2 documented municipal building permits on file
On-parcel permit history is indexed through Jun 8, 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)
- ✓ 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)
- ! Delayed or open permit activity on this parcel
Accessory dwelling unit at 40 Garden Rock Rd: In "Applied" for 5.4 yr (since Jun 8, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
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 99 Garden Rock Rd (0.14 mi NW, 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:
- 14,680 sq ft (0.34 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 40 GARDEN ROCK RD
Zoning & Land Use
R1-BD — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-BD (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-BD, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-BD, a single-family residential zone. The lot is 14,680 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
- 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: $1,690,000 – $2,150,000 · 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
Nearby Activity (½ mile radius, since November 2024)
2 active or recent development projects (1 housing units across completed, permitted, and pipeline stages) and 204 total building permits recorded within ½ mile.
- New construction9 permits
- Adds housing (ADU)1 permit (1 units)
- Demolition2 permits
- Additions & renovations24 permits
- Building systems143 permits
- Repairs4 permits
- Other21 permits
Developments Deserving Closer Investigation & Active Area Builders
- Accessory dwelling unit at 40 Garden Rock Rd (Applied)On this parcel
In "Applied" for 5.4 yr (since Jun 8, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- New home at 99 Garden Rock Rd (Applied)0.14 mi NW
In "Applied" for 3.1 yr (since Oct 11, 2023), 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, $1,200,000 declared valuation across 1 permit).
- Accessory dwelling unit (new or conversion) (88386) (Applied)On this parcel
Pending in review for 5.4 yr (9.7× the 204d median) — slower than 90% of accessory dwelling unit (new or conversion) permits in Unincorporated Marin (median 204d, 90th pct 549d, n=298).
- New commercial building at 1500 Butterfield Rd (Issued)0.29 mi NE
Active in "Issued" for 4 yr (first record Oct 25, 2022) with no new permit activity recorded in 12 mo. High-impact scale ($2,700,000 declared valuation across 2 permits).
Entity-resolved builders & contractors in ½ mile: Owner (1 on parcel, 14 in ½ mi · New garage / accessory structure); Owner Builder (17 in ½ mi · Remodel / interior alteration); Cedar House Construction (6 in ½ mi · New garage / accessory structure); Levine Design And Construction (5 in ½ mi · New garage / accessory structure); Fisher Development (4 in ½ mi · Commercial tenant improvement).
Permit & Project History on This Parcel (2 permits, 1 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 88386 | Accessory dwelling unit (new or conversion) | Applied | App. Jun 8, 2021 | $15,000 | Legalize Garage Conversion To A D U |
| 147708 | Electrical / panel | Issued | Iss. Jun 25, 2015 | $1,000 | New 200amp Electrical Service |