400 Tennessee Glen Way
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.87382, -122.52557
Executive Verdict · Public-Records Synthesis
Zoned RMP-0.5 in Unincorporated Marin with likely ministerial ADU eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,252,000 ($1,982,000–$2,522,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-0.5 allows residential use qualifying for ministerial ADU review under state law (1 ADU permit 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 Nov 6, 2026, 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 Tamalpais
50 substantial renovation & housing permits over 24 months (20.5 per 1,000 parcels vs. 16.4 citywide baseline) (#3 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Tamalpais)
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 High 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: New home at 535 Tennessee Valley Rd (adu 531) (0.11 mi 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 (~$26,348/yr at $2,252,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,196/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:
- 18,208 sq ft (0.42 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 400 TENNESSEE GLEN WAY
Zoning & Land Use
RMP-0.5 — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-0.5 (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-0.5 (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-0.5 (multifamily residential), not a single-family residential zone.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- High 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 06041C0507E, 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: $1,982,000 – $2,522,000 · 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
- New home at 535 Tennessee Valley Rd (adu 531) (Issued)0.11 mi S
Active in "Issued" for 6 yr (first record Oct 29, 2020) with no new permit activity recorded in 4 yr. High-impact scale (1 housing unit, $800,000 declared valuation across 1 permit).
- New commercial building at 201 Flamingo Rd (aka 205) (Issued)0.49 mi N
Active in "Issued" for 11.7 yr (first record Feb 17, 2015) with no new permit activity recorded in 11.2 yr. High-impact scale ($3,938,400 declared valuation across 3 permits).
- Accessory dwelling unit at 387 Countyview Dr (Applied)0.47 mi W
In "Applied" for 5.2 yr (since Sep 3, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Accessory dwelling unit at 318 Via Recodo (Applied)0.47 mi SW
In "Applied" for 7.4 yr (since Jun 25, 2019), 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: Peter Levi Plumbing (3 on parcel, 3 in ½ mi · HVAC / heat pump); Owner Builder (36 in ½ mi · Remodel / interior alteration); Owner (30 in ½ mi · Remodel / interior alteration); Ga Higgins (10 in ½ mi · Remodel / interior alteration); Rods General Builders (7 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (3 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B49038 | Plumbing / water heater / sewer | Issued | Iss. Nov 6, 2026 | $15,000 | Replace Plumbing Fixtures(s) |
| B28721 | Plumbing / water heater / sewer | Issued | Iss. Feb 14, 2022 | $12,000 | Excavate a trench from meter to home, water line service replacement approx 120 ft — Replace Plumbing Fixtures(s) |
| B25268 | HVAC / heat pump | Issued | Iss. Mar 25, 2021 | $9,319 | 96% 70k btu fAU CHANGE OUT UNDER HOUSE, LIKE FOR LIKE — Replace Mechanical Appliance |