601 Glenwood Ave
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.87954, -122.54626
Executive Verdict · Public-Records Synthesis
Zoned RA-B2 in Unincorporated Marin with likely ministerial ADU eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,179,000 ($1,918,000–$2,440,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RA-B2 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
- ✓ Documented permitted upgrades (+$40,461 contributory est.)
Public building records show issued construction/renovation work on this parcel (9 total permits, latest Dec 5, 2022).
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. 16.3 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: Accessory dwelling unit at 875 Marin Dr (0.34 mi S, 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 (~$25,509/yr at $2,179,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,126/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:
- 9,191 sq ft (0.21 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 601 GLENWOOD AVE
Zoning & Land Use
RA-B2 — Residential Agriculture (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RA-B2 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotCan't tell
Zoned RA-B2 (single-family residential): we can't tell whether it counts as a single-family zone for SB 9. Residential agriculture, estate and restricted: large-lot residential; confirm SB 9 with the county.
- SB 9: split into two lotsCan't tell
Zoned RA-B2 (single-family residential): we can't tell whether it counts as a single-family zone for SB 9. Residential agriculture, estate and restricted: large-lot residential; confirm SB 9 with the county.
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 06041C0468F, 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: $1,918,000 – $2,440,000 · 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
- Accessory dwelling unit at 875 Marin Dr (Applied)0.34 mi S
In "Applied" for 2.6 yr (since Apr 11, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). Record changed to "updated" in snapshot Nov 4, 2026.
- New home at 812 Spring Dr (Issued)0.28 mi SE
Active in "Issued" for 4.2 yr (first record Sep 19, 2022) with no new permit activity recorded in 3.3 yr. High-impact scale (1 housing unit, $1,006,000 declared valuation across 1 permit).
- New home at 808 Spring Dr (Issued)0.3 mi SE
Active in "Issued" for 4.9 yr (first record Dec 13, 2021) with no new permit activity recorded in 4.7 yr. High-impact scale (1 housing unit, $850,000 declared valuation across 1 permit).
- New home at 731 Bay Rd (Issued)0.31 mi E
Active in "Issued" for 18 mo (first record May 12, 2025) with no new permit activity recorded in 15 mo. High-impact scale (1 housing unit, $955,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Owner (2 on parcel, 28 in ½ mi · Remodel / interior alteration); Bellows Plumbing Heating And Air (1 on parcel, 2 in ½ mi · Accessory dwelling unit (new or conversion)); Wedge Roofing (1 on parcel, 1 in ½ mi · Solar / battery storage); Tesla Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Swell Services (1 on parcel, 1 in ½ mi · Solar / battery storage).
Permit & Project History on This Parcel (9 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B31935 | Solar / battery storage | Issued | Iss. Dec 5, 2022 | $20,581 | INSTALL ADVANCED ENERGY SYSTEM: (1) TESLA POWERWALL 2 AC BATTERY SYSTEM (5KW, 13.5KWH) (1) TESLA BACKUP GATEWAY 2 WITH I… |
| B30535 | Solar / battery storage | Issued | Iss. Jul 28, 2022 | $4,752 | 2.88kW BIPV system. 64 solar modules, 1 inverter. |
| B30350 | Solar / battery storage | Issued | Iss. Jul 12, 2022 | $45,100 | Remove existing33 sq ft roof down to sheathing. Prepare existing sheathing for new roof. Install GAF Timberline Solar Ro… |
| 165076 | Roof replacement | Issued | Iss. Jul 9, 2020 | $9,510 | Re-Roof |
| 165075 | Solar / battery storage | Issued |