27 Rock Rd
Kentfield 94904 · Kentfield · Unincorporated Marin · Coordinates: 37.95410, -122.56121
Executive Verdict · Public-Records Synthesis
Zoned RSP-1 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 $2,696,000 ($2,372,000–$3,020,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned RSP-1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 34,717 sq ft lot. Local precedent is active with 5 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$227,160 contributory est.)
Public building records show issued construction/renovation work on this parcel (12 total permits, latest Aug 20, 2025).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Kentfield
104 substantial renovation & housing permits over 24 months (41.3 per 1,000 parcels vs. 16.4 citywide baseline) (#7 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Kentfield)
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 (179410): Issued after 12 mo (4.4× 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: Accessory dwelling unit at 432 Woodland Rd (0.27 mi S, 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:
- 34,717 sq ft (0.80 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 27 ROCK RD
Zoning & Land Use
RSP-1 — Residential Single Family Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RSP-1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned RSP-1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned RSP-1, a single-family residential zone. The lot is 34,717 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 06041C0458F, effective March 16, 2016
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $2,372,000 – $3,020,000 · Status: Off market
HUD Small Area FMR (ZIP 94904) · FY 2026
Studio $2,260 · 1BR $2,710 · 2BR $3,280 · 3BR $4,190 · 4BR $4,340
Developments Deserving Closer Investigation & Active Area Builders
- Accessory dwelling unit at 432 Woodland Rd (Applied)0.27 mi S
In "Applied" for 2.6 yr (since Apr 12, 2024), 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, $1,250,000 declared valuation across 1 permit).
- General repair (179410) (Issued)On this parcel
Issued after 12 mo (4.4× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
- General repair (92280) (Applied)On this parcel
Pending in review for 2.4 yr (10.7× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
- New home at 75 Rock Rd (Issued)0.15 mi E
Active in "Issued" for 2.2 yr (first record Aug 27, 2024) with no new permit activity recorded in 18 mo. High-impact scale (1 housing unit, $936,400 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Ldc (3 on parcel, 3 in ½ mi · General repair); Ongaro Ernest And Sons (2 on parcel, 2 in ½ mi · HVAC / heat pump); Nexus Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Bluestone Pool And Landscape (1 on parcel, 1 in ½ mi · New garage / accessory structure); Mccauleys And Father Const (1 on parcel, 1 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (12 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B43564 | Solar / battery storage | Issued | Iss. Aug 20, 2025 | $106,000 | Install 21.75kw solar system, 50 panels 50 micro, 3 Enphase batteries |
| 179410 | General repair | Issued | Iss. Jun 9, 2025 | $40,000 | Retaining Wall & Rebuild Landscape Stairs With Handrail |
| 92280 | General repair | Applied | App. Jun 4, 2024 | $82,000 | Retaining Wall |
| 174728 | General repair | Issued | Iss. Aug 10, 2023 | $82,000 | Retaining Wall |
| 174727 | Addition (adds square footage) | Issued | Iss. Aug 10, 2023 | $728,000 |