20 Elm Ave
Kentfield 94904 · Kentfield · Unincorporated Marin · Coordinates: 37.95781, -122.54766
Executive Verdict · Public-Records Synthesis
Zoned R1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,343,000 ($2,062,000–$2,624,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 12,284 sq ft lot. Local precedent is active with 5 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ 1 documented municipal building permit on file
On-parcel permit history is indexed through Aug 27, 2025, letting you verify roof, HVAC, electrical, or structural work against seller disclosures.
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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 66 Hanken Dr (adu 66a) (490 ft N, issued). 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 (~$27,395/yr at $2,343,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,283/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:
- 12,284 sq ft (0.28 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 20 ELM AVE
Zoning & Land Use
R1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1, a single-family residential zone. The lot is 12,284 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: 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: $2,062,000 – $2,624,000 · 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 66 Hanken Dr (adu 66a) (Issued)490 ft N
Active in "Issued" for 3.1 yr (first record Sep 29, 2023) with no new permit activity recorded in 2.8 yr. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
- New home at 7 Cedar Ave (Issued)0.25 mi SW
Active in "Issued" for 7.7 yr (first record Mar 14, 2019) with no new permit activity recorded in 5.5 yr. High-impact scale (1 housing unit, $1,217,500 declared valuation across 2 permits).
- New home at 105 Oak Ave (Issued)0.33 mi SE
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).
- Accessory dwelling unit at 22 Maple Ave (Applied)300 ft SE
In "Applied" for 5.9 yr (since Jan 4, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Entity-resolved builders & contractors in ½ mile: Kearney Construction (1 on parcel, 1 in ½ mi · Other); Owner (37 in ½ mi · Remodel / interior alteration); Owner Builder (35 in ½ mi · Remodel / interior alteration); Juan Calmell (7 in ½ mi · Remodel / interior alteration); Hendrickson Pools (6 in ½ mi · Pool / spa).
Permit & Project History on This Parcel (1 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B43637 | Other | Issued | Iss. Aug 27, 2025 | $45,000 | Replace Kitchen Cabinets and counters, remodel bath. No structural changes |