145 Hidden Valley Ln
San Anselmo 94960 · Sleepy Hollow · Unincorporated Marin · Coordinates: 38.00773, -122.57645
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 $1,997,000 ($1,757,000–$2,237,000).
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 45,564 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ 5 documented municipal building permits on file
On-parcel permit history is indexed through Aug 7, 2024, 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
General repair (90312): Pending in review for 4.2 yr (18.3× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
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 40 De Burgh Dr (0.43 mi W, 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:
- 45,564 sq ft (1.05 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 145 HIDDEN VALLEY LN
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 45,564 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: $1,757,000 – $2,237,000 · 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)0.43 mi W
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).
- General repair (90312) (Applied)On this parcel
Pending in review for 4.2 yr (18.3× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
- Addition (adds square footage) (90235) (Applied)On this parcel
Pending in review for 4.2 yr (9.7× the 160d median) — slower than 90% of addition (adds square footage) permits in Unincorporated Marin (median 160d, 90th pct 440d, n=316).
- New home at 830 Butterfield Rd (Issued)0.33 mi S
Active in "Issued" for 8.3 yr (first record Aug 9, 2018) with no new permit activity recorded in 7.6 yr. High-impact scale (1 housing unit, $1,097,000 declared valuation across 2 permits).
Entity-resolved builders & contractors in ½ mile: Northern Pacific Roofing (2 on parcel, 2 in ½ mi · Roof replacement); Bay Area Window Pros (1 on parcel, 1 in ½ mi · Windows / doors / siding); Owner Builder (31 in ½ mi · Remodel / interior alteration); Owner (9 in ½ mi · Remodel / interior alteration); First Impressions Painting And Building (4 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B39032 | Windows / doors / siding | Issued | Iss. Aug 7, 2024 | $120,000 | REMOVE EXISTING SIDING AND REPLACE WITH CLASS A JAMES HARDIE SIDING — Siding Replacement |
| B39031 | Roof replacement | Issued | Iss. Aug 7, 2024 | $27,866 | Tear off existing roof and replace with a class A composition shingle roof system. — ReRoofing; With Electronic Inspecti… |
| B38074 | Windows / doors / siding | Issued | Iss. May 16, 2024 | $108,000 | Replace 38 windows and 1 Patio door, the same sizes and locations. — Non-structural Door/Window Replacement |
| 90312 | General repair | Applied | App. Sep 15, 2022 | $20,000 | Retaining Wall |
| 90235 | Addition (adds square footage) |