100 Stadium Ave
Mill Valley 94941 · Almonte · Unincorporated Marin · Coordinates: 37.89036, -122.52956
Executive Verdict · Public-Records Synthesis
Zoned RMP-22 in Unincorporated Marin with likely ministerial ADU eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,140,000 ($1,883,000–$2,397,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-22 allows residential use qualifying for ministerial ADU review under state law (2 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ 2 documented municipal building permits on file
On-parcel permit history is indexed through Nov 10, 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)
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)
- ! Delayed or open permit activity on this parcel
General repair (93700): Pending in review for 12 mo (4.4× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 5 slow or stalled nearby projects within ½ mile
Closest lead: New home at 125 Morning Sun Ave (490 ft S, 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 (~$25,060/yr at $2,140,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,088/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:
- 8,625 sq ft (0.20 ac)
- Assessor use:
- Multiple-Resid. - Improved
- Addresses on lot:
- 100 STADIUM AVE
Zoning & Land Use
RMP-22 — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-22 (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-22 (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-22 (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 X: minimal flood hazard (all 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: $1,883,000 – $2,397,000 · 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
Developments Deserving Closer Investigation & Active Area Builders
- General repair (93700) (Applied)On this parcel
Pending in review for 12 mo (4.4× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
- New home at 125 Morning Sun Ave (Issued)490 ft S
Active in "Issued" for 8.1 yr (first record Oct 15, 2018) with no new permit activity recorded in 7.8 yr. High-impact scale (1 housing unit, $900,000 declared valuation across 3 permits).
- Accessory dwelling unit at 131 Yale Ave A (Issued)0.17 mi S
Active in "Issued" for 4.8 yr (first record Jan 19, 2022) with no new permit activity recorded in 3.4 yr. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
- New commercial building at 100 Harvard Ave (Issued)0.23 mi SW
Active in "Issued" for 23 mo (first record Dec 26, 2024) with no new permit activity recorded in 18 mo. High-impact scale ($6,500,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Michael A Martin (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Owner Builder (78 in ½ mi · Remodel / interior alteration); Owner (36 in ½ mi · Remodel / interior alteration); Miette (6 in ½ mi · Remodel / interior alteration); Juan Calmell (6 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 93700 | General repair | Applied | App. Nov 10, 2025 | $3,575 | Extend Existing Retaining Wall B W O P |
| B11325 | Plumbing / water heater / sewer | Issued | Iss. Nov 7, 2016 | $50,600 | replace siding, windows, replace plumbing fixtures in kitchen and bath, replace switches and outlets water repair — Repl… |