99 Garden Rock Rd
San Anselmo 94960 · Sleepy Hollow · Unincorporated Marin · Coordinates: 38.01583, -122.59301
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 $2,369,000 ($2,085,000–$2,653,000).
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 30,666 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
- ✓ Documented permitted upgrades (+$372,000 contributory est.)
Public building records show issued construction/renovation work on this parcel (10 total permits, latest Jun 3, 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)
- ! Delayed or open permit activity on this parcel
New home at 99 Garden Rock Rd: 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).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 2 slow or stalled nearby projects within ½ mile
Closest lead: New commercial building at 1500 Butterfield Rd (0.38 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:
- 30,666 sq ft (0.70 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 99 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 30,666 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: $2,085,000 – $2,653,000 · 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 99 Garden Rock Rd (Applied)On this parcel
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).
- General repair (91590) (Applied)On this parcel
Pending in review for 3.1 yr (13.5× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
- New garage / accessory structure (91589) (Applied)On this parcel
Pending in review for 3.1 yr (6.8× the 164d median) — slower than 90% of new garage / accessory structure permits in Unincorporated Marin (median 164d, 90th pct 485d, n=356).
- New single-family home (91571) (Applied)On this parcel
Pending in review for 3.1 yr (4.5× the 253d median) — slower than 90% of new single-family home permits in Unincorporated Marin (median 253d, 90th pct 686d, n=121).
Entity-resolved builders & contractors in ½ mile: Hartwell Constr (3 on parcel, 3 in ½ mi · Addition (adds square footage)); Singlepoint Design Build (2 on parcel, 2 in ½ mi · Addition (adds square footage)); Grid Titans (1 on parcel, 1 in ½ mi · Other); Zaragoza Plumbing Team (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Owner Builder (15 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (10 permits, 1 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B47015 | Other | Issued | Iss. Jun 3, 2026 | $42,531 | — |
| 181685 | New garage / accessory structure | Issued | Iss. May 15, 2026 | $75,000 | Replace Detached Garage; Trellis; (N) Retaining Wall; Steps On Grade |
| 180036 | Addition (adds square footage) | Issued | Iss. Sep 9, 2025 | $750,000 | Addition & Remodel; Retaining Wall & Misc Site Improvements Incl (N) Drvieway |
| 91590 | General repair | Applied | App. Oct 17, 2023 | $120,000 | Southwest Retaining Wall - Associated W/ (N) S F D |