21 Oak Knoll Rd
Kentfield 94904 · Kentfield · Unincorporated Marin · Coordinates: 37.94703, -122.55230
Executive Verdict · Public-Records Synthesis
Zoned R1-B2 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 $2,493,000 ($2,194,000–$2,792,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B2 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 30,928 sq ft lot. Local precedent is active with 4 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$24,000 contributory est.)
Public building records show issued construction/renovation work on this parcel (4 total permits, latest Jul 7, 2016).
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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: Magnolia Village (0.49 mi E, entitled). Inspect timeline history before assuming near-term completion.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · HCD APR (½-mile radius)
- ! Year 1 Prop 13 tax reset (~$29,120/yr at $2,493,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,427/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector
Parcel & Assessor
- Lot size:
- 30,928 sq ft (0.71 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 21 OAK KNOLL RD
Zoning & Land Use
R1-B2 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B2 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B2, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B2, a single-family residential zone. The lot is 30,928 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: $2,194,000 – $2,792,000 · 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
- Magnolia Village (Entitled)0.49 mi E
In "Entitled" for 3.8 yr (since Feb 1, 2023), exceeding the 292d median and 313d 90th percentile for new multifamily / condos / mixed-use permits in Unincorporated Marin (n=21). High-impact scale (20 housing units, 4 deed-restricted affordable across 0 permits).
- New home at 100 Black Log Rd (Applied)0.41 mi S
In "Applied" for 10.7 yr (since Feb 22, 2016), 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, $1,400,000 declared valuation across 1 permit).
- New home at 617 College Ave (Issued)0.22 mi NE
Active in "Issued" for 13 yr (first record Nov 12, 2013) with no new permit activity recorded in 12.7 yr. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
- Accessory dwelling unit at 625 College Ave (a D U 627) (Issued)0.25 mi NE
Active in "Issued" for 3.9 yr (first record Dec 7, 2022) with no new permit activity recorded in 3 yr. High-impact scale (1 housing unit, $4,500,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Marco Design Group (4 on parcel, 4 in ½ mi · General repair); Owner Builder (35 in ½ mi · Remodel / interior alteration); Owner (11 in ½ mi · Remodel / interior alteration); Swett Construction (9 in ½ mi · New garage / accessory structure); Fairweather And Associates (8 in ½ mi · Demolition).
Permit & Project History on This Parcel (4 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 152646 | General repair | Issued | Iss. Jul 7, 2016 | $10,000 | Retaining Wall @ Pool (Near B B Q) |
| 152645 | General repair | Issued | Iss. Jul 7, 2016 | $10,000 | Retaining Wall @ Pool(Near Fire Pit) |
| 152644 | General repair | Issued | Iss. Jul 7, 2016 | $10,000 | Retaining Wall Behind Pool (East Of Pool)***Expired |
| 152643 | Pool / spa | Issued | Iss. Jul 7, 2016 | $80,000 | Pool & Spa |