250 Hillside Ave
Kentfield 94904 · Kentfield · Unincorporated Marin · Coordinates: 37.95446, -122.55606
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 $2,485,000 ($2,187,000–$2,783,000).
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 33,280 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 (+$16,560 contributory est.)
Public building records show issued construction/renovation work on this parcel (8 total permits, latest Aug 25, 2026).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Kentfield
103 substantial renovation & housing permits over 24 months (40.9 per 1,000 parcels vs. 16.3 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: Accessory dwelling unit at 432 Woodland Rd (0.47 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)
- ! Year 1 Prop 13 tax reset (~$29,028/yr at $2,485,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,419/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:
- 33,280 sq ft (0.76 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 250 HILLSIDE AVE
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 33,280 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: $2,187,000 – $2,783,000 · 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 301 total building permits recorded within ½ mile.
- New construction16 permits (6 units)
- Adds housing (ADU)8 permits (8 units)
- Demolition8 permits
- Additions & renovations30 permits
- Building systems189 permits
- Repairs18 permits
- Other32 permits
Developments Deserving Closer Investigation & Active Area Builders
- Accessory dwelling unit at 432 Woodland Rd (Applied)0.47 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).
- New home at 75 Rock Rd (Issued)0.14 mi W
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)0.31 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).
- Accessory dwelling unit at 625 College Ave (a D U 627) (Issued)0.44 mi SE
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: Ernest Ongaro And Sons (3 on parcel, 4 in ½ mi · Accessory dwelling unit (new or conversion)); Mc Leran (1 on parcel, 1 in ½ mi · Roof replacement); Green Bay Remodeling (1 on parcel, 1 in ½ mi · Other); Divine Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (38 in ½ mi · Addition (adds square footage)).
Permit & Project History on This Parcel (8 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 94484 | Pool / spa | Applied | App. Aug 25, 2026 | $400,000 | Pool Remodel (N) Auto Pool Cover (N) Spa (N) Spa Deck (N) Outdoor Kitchen And Bar (N) Fire Pit (N) Landscape And Retaini… |
| B40428 | EV charger | Issued | Iss. Dec 4, 2024 | $3,400 | Replace 125a main panel with 200a main panel in existing location. Install 50a dedicated circuit in garage for Porsche E… |
| B40169 | Solar / battery storage | Issued | Iss. Nov 13, 2024 | $72,548 | New PV Roof mounted system - 13.860 KW DC/12.745 KW CEC AC & ESS 20.0 kwh 33 solar panels & 4 Enphase back up batteries |
| B38531 | Other | Issued | Iss. Jun 27, 2024 | $25,000 | Non-structural Bathroom Remodel |
| B38285 | HVAC / heat pump | Issued | Iss. Jun 5, 2024 | $31,500 | Replace ducting with new ducting, replace furnace with air handler and install heat pump new — Replace Ductwork, Mechani… |
| B36425 | Electrical / panel | Issued | Iss. Dec 14, 2023 | $7,000 | New 30a 240v circuit for dryer. 20a 120v circuit for pool cover. 2 20a 240v circuits for garage. 2 new recessed lights +… |
| B23890 | Roof replacement | Issued | Iss. Oct 20, 2020 | $41,850 | Tear off main roof to solid sheeting. Re-roof with Class A Lifetime Shingles. — ReRoofing; With Electronic Inspection |
| 163497 | Electrical / panel | Issued | Iss. Dec 10, 2019 | $5,000 | Upgrade To 125 A & Reloc Meter Main; Repl 2 Sub Panels |