70 Rock Rd
Kentfield 94904 · Kentfield · Unincorporated Marin · Coordinates: 37.95529, -122.55657
Executive Verdict · Public-Records Synthesis
Zoned R1-B3 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 $2,555,000 ($2,248,000–$2,862,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B3 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 84,811 sq ft lot. Local precedent is active with 2 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$85,800 contributory est.)
Public building records show issued construction/renovation work on this parcel (6 total permits, latest Dec 22, 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
Remodel / interior alteration (155045): Issued after 12 mo (4.2× the 83d median) — slower than 90% of remodel / interior alteration permits in Unincorporated Marin (median 83d, 90th pct 266d, n=1,054).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 5 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 432 Woodland Rd (0.49 mi SW, 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:
- 84,811 sq ft (1.95 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 70 ROCK RD
Zoning & Land Use
R1-B3 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B3 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B3, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B3, a single-family residential zone. The lot is 84,811 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: $2,248,000 – $2,862,000 · 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
Nearby Activity (½ mile radius, since November 2024)
23 active or recent development projects (19 housing units across completed, permitted, and pipeline stages) and 292 total building permits recorded within ½ mile.
- New construction15 permits (6 units)
- Adds housing (ADU)8 permits (8 units)
- Demolition8 permits
- Additions & renovations28 permits
- Building systems188 permits
- Repairs16 permits
- Other29 permits
Developments Deserving Closer Investigation & Active Area Builders
- Accessory dwelling unit at 432 Woodland Rd (Applied)0.49 mi SW
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).
- Remodel / interior alteration (155045) (Issued)On this parcel
Issued after 12 mo (4.2× the 83d median) — slower than 90% of remodel / interior alteration permits in Unincorporated Marin (median 83d, 90th pct 266d, n=1,054).
- New home at 75 Rock Rd (Issued)0.12 mi SW
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).
- Accessory dwelling unit at 31 N Ridgewood Rd (adu 31a) (Issued)0.34 mi SW
Active in "Issued" for 20 mo (first record Feb 28, 2025) with no new permit activity recorded in 16 mo. High-impact scale (1 housing unit, $750,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Owner Builder (1 on parcel, 26 in ½ mi · Addition (adds square footage)); Nyberg Construction (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Clean Cut Builder (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Divine Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner (17 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (6 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 180735 | Remodel / interior alteration | Issued | Iss. Dec 22, 2025 | $100,000 | Remodel 3rd Flr Incl Windows & Doors; Replace Wood Burning Fireplace/W (3) Decorative Gas Fireplaces |
| B23769 | Electrical / panel | Issued | Iss. Oct 7, 2020 | $7,800 | -Install 100A/50A single Circuit Transfer Switch and inlet, opposite Main Panel. Includes adding missing grounding condu… |
| 158181 | Remodel / interior alteration | Issued | Iss. Apr 11, 2018 | $20,000 | Rmdl And Adding New Door T.D. 3/29/18 |
| 157256 | Remodel / interior alteration | Issued | Iss. Dec 12, 2017 | $42,500 | Kitch Rmld- Express |
| 155045 | Remodel / interior alteration | Issued | Iss. Mar 29, 2017 | $30,000 | Conv Sp Under Gar - Workout Room W/ Wet Bar, 1 Bath, 1bed (Office) T.D. 5/5/16 |
| 150431 | Electrical / panel | Issued | Iss. Jan 20, 2016 | $2,500 | Repl Main Elec Serv Panel |