23 Spring Rd
Kentfield 94904 · Kentfield · Unincorporated Marin · Coordinates: 37.95503, -122.56446
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 $2,665,000 ($2,345,000–$2,985,000).
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 78,060 sq ft lot. Local precedent is active with 1 ADU permit within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$195,900 contributory est.)
Public building records show issued construction/renovation work on this parcel (13 total permits, latest Feb 4, 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 (92008): Pending in review for 2.7 yr (11.7× 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 (0.32 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:
- 78,060 sq ft (1.79 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 23 SPRING 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 78,060 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 06041C0454E, effective March 17, 2014
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $2,345,000 – $2,985,000 · 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)0.32 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).
- Remodel / interior alteration (92008) (Applied)On this parcel
Pending in review for 2.7 yr (11.7× 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 15 Spring Rd (Issued)270 ft W
Active in "Issued" for 11.4 yr (first record Jun 24, 2015) with no new permit activity recorded in 11.1 yr. High-impact scale (1 housing unit, $2,745,000 declared valuation across 1 permit).
- New home at 75 Rock Rd (Issued)0.32 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: Owner (2 on parcel, 6 in ½ mi · Remodel / interior alteration); La Solar Group (2 on parcel, 2 in ½ mi · Other); North HVAC Services (2 on parcel, 2 in ½ mi · HVAC / heat pump); Mw General Construction (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Bayline Construction (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer).
Permit & Project History on This Parcel (13 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B41109 | Other | Issued | Iss. Feb 4, 2025 | $17,000 | 2 x Tesla Powerwall 2, Backup gateway. |
| B38890 | Plumbing / water heater / sewer | Issued | Iss. Jul 31, 2024 | $8,000 | Install new portable Hot Tub Circuit (220 volt UG), and connect to Outdoor Hot Tub. Relocate 120 volt indoor electrical … |
| 92008 | Remodel / interior alteration | Applied | App. Mar 18, 2024 | $15,000 | Convert (E) Garage To (N) Living Space |
| B36771 | Electrical / panel | Issued | Iss. Jan 22, 2024 | $5,000 | Underground current overhead power line to house in same location — Service Upgrade |
| 175703 | Remodel / interior alteration | Issued |