6 Rosebank Ave
Kentfield 94904 · Kentfield · Unincorporated Marin · Coordinates: 37.95323, -122.54177
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,250,000 ($1,980,000–$2,520,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 6,839 sq ft lot. Local precedent is active with 7 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$10,560 contributory est.)
Public building records show issued construction/renovation work on this parcel (4 total permits, latest Feb 20, 2023).
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: 0.2% annual chance flood hazard (shaded X))
all of the lot of the parcel intersects Zone X: 0.2% annual chance flood hazard (shaded X). Outside mandatory federal SFHA insurance rules, but check local drainage and finished-floor requirements.
Source: FEMA National Flood Hazard Layer (parcel polygon)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 34 Wolfe Grade (0.34 mi E, 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)
- ! Year 1 Prop 13 tax reset (~$26,325/yr at $2,250,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,194/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:
- 6,839 sq ft (0.16 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 6 ROSEBANK AVE
Zoning & Land Use
R1-B1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B1, a single-family residential zone. The lot is 6,839 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
- Not in a State-mapped fire hazard severity zone
- FEMA National Flood Hazard Layer
- Zone X: 0.2% annual chance flood hazard (shaded X) (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: $1,980,000 – $2,520,000 · 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 34 Wolfe Grade (Applied)0.34 mi E
In "Applied" for 2.8 yr (since Jan 17, 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, $750,000 declared valuation across 1 permit).
- New home at 105 Oak Ave (Issued)0.15 mi N
Active in "Issued" for 4.3 yr (first record Jul 15, 2022) with no new permit activity recorded in 14 mo. High-impact scale (1 housing unit, $965,000 declared valuation across 3 permits).
- New home at 49 Laurel Grove Ave (Issued)0.21 mi N
Active in "Issued" for 9.3 yr (first record Jul 18, 2017) with no new permit activity recorded in 9.1 yr. High-impact scale (1 housing unit, $1,200,000 declared valuation across 1 permit).
- Accessory dwelling unit at 625 College Ave (a D U 627) (Issued)0.49 mi SW
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: Sunrun Installation Service (2 on parcel, 2 in ½ mi · Solar / battery storage); Northern Pacific Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Strom Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (52 in ½ mi · Remodel / interior alteration); Owner (42 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (4 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B32668 | Roof replacement | Issued | Iss. Feb 20, 2023 | $11,140 | Tear off existing roof and reroof with Class A roof system. — ReRoofing |
| B19998 | Electrical / panel | Issued | Iss. Oct 1, 2019 | $5,000 | Replace the main panel and relocate the sub-panel — Service Upgrade |
| 158244 | Solar / battery storage | Issued | Iss. Apr 18, 2018 | $13,700 | Battery Backup - Express |
| 156921 | Solar / battery storage | Issued | Iss. Oct 31, 2017 | $10,500 | P V Sys 5.61 K W - Express***Expired |