915 E Blithedale Ave
Mill Valley 94941 · Alto · Unincorporated Marin · Coordinates: 37.90388, -122.51805
Executive Verdict · Public-Records Synthesis
Zoned RMP-40 in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AO flood due diligence; benchmark value $2,176,000 ($1,915,000–$2,437,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-40 allows residential use qualifying for ministerial ADU review under state law (8 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ 3 documented municipal building permits on file
On-parcel permit history is indexed through Apr 6, 2017, 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)
Watchouts & Due Diligence
- ! FEMA Special Flood Hazard Area (AO, about 6% of the lot of lot)
Zone AO: 1% annual chance flood (Special Flood Hazard Area) overlaps this parcel. Expect mandatory flood insurance for federally backed loans and floodplain elevation/mitigation rules for new units or SB 9 applications.
Source: FEMA National Flood Hazard Layer (parcel polygon)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home at 55 Thomas Dr (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 (~$25,474/yr at $2,176,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,123/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:
- 11,282 sq ft (0.26 ac)
- Assessor use:
- Multiple-Resid. - Improved
- Addresses on lot:
- 915 E BLITHEDALE AVE
Zoning & Land Use
RMP-40 — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-40 (multifamily residential): state law allows ADUs where homes are allowed. On a multifamily lot the state allowance is different: ADUs in non-living space of the building, plus up to eight detached ADUs.
- SB 9: two homes on the lotUnlikely
Zoned RMP-40 (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-40 (multifamily residential), not a single-family residential zone.
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 AO: 1% annual chance flood (Special Flood Hazard Area) (about 6% of the lot); Zone X: minimal flood hazard (about 94% of the lot) · FIRM panel 06041C0469F, 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: $1,915,000 – $2,437,000 · Status: Off market
HUD Small Area FMR (ZIP 94941) · FY 2026
Studio $2,730 · 1BR $3,270 · 2BR $3,960 · 3BR $5,060 · 4BR $5,240
Nearby Activity (½ mile radius, since November 2024)
11 active or recent development projects (11 housing units across completed, permitted, and pipeline stages) and 191 total building permits recorded within ½ mile.
- New construction3 permits (1 units)
- Adds housing (ADU)8 permits (8 units)
- Demolition2 permits
- Additions & renovations27 permits
- Building systems129 permits
- Repairs2 permits
- Other20 permits
Developments Deserving Closer Investigation & Active Area Builders
- New home at 55 Thomas Dr (Applied)0.34 mi E
In "Applied" for 6.2 yr (since Sep 1, 2020), 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, $1,000,000 declared valuation across 1 permit).
- Accessory dwelling unit at 55 Plaza Dr (adu 55a) (Issued)180 ft N
Active in "Issued" for 2.6 yr (first record Apr 17, 2024) with no new permit activity recorded in 19 mo. High-impact scale (1 housing unit, $790,000 declared valuation across 1 permit).
- New home at 30 Shell Rd (Issued)0.18 mi N
Active in "Issued" for 2.4 yr (first record Jul 5, 2024) with no new permit activity recorded in 22 mo. High-impact scale (1 housing unit, $2,800,000 declared valuation across 1 permit).
- New home at 55 S Knoll Rd (Issued)0.42 mi SE
Active in "Issued" for 11.9 yr (first record Dec 22, 2014) with no new permit activity recorded in 11.4 yr. High-impact scale (1 housing unit, $750,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Owner Builder (1 on parcel, 42 in ½ mi · Remodel / interior alteration); Anderton Construction (1 on parcel, 1 in ½ mi · General repair); Aaero Heating And Sheet Metal (1 on parcel, 1 in ½ mi · HVAC / heat pump); Owner (22 in ½ mi · Remodel / interior alteration); Drosihn Construction (7 in ½ mi · New single-family home).
Permit & Project History on This Parcel (3 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 155120 | HVAC / heat pump | Issued | Iss. Apr 6, 2017 | $1,740 | Repl Furnace |
| 152247 | General repair | Issued | Iss. Jun 8, 2016 | $3,500 | Repair Deck***Expired 5/23/16 |
| 151174 | General repair | Issued | Iss. Mar 14, 2016 | $2,229 | Repl 6 Joists On Deck***Expired |