534 Marin Ave
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.88041, -122.54222
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 (local responsibility area) due diligence; benchmark value $2,212,000 ($1,947,000–$2,477,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RA-B2 allows residential use qualifying for ministerial ADU review under state law (4 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$21,182 contributory est.)
Public building records show issued construction/renovation work on this parcel (6 total permits, latest Jan 12, 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. 16.4 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 (Local 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 Mar 24, 2025)
- ! Delayed or open permit activity on this parcel
Remodel / interior alteration (169226): Issued after 14 mo (5.1× the 83d median) — slower than 90% of remodel / interior alteration permits in Unincorporated Marin (median 83d, 90th pct 266d, n=1,054).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 4 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 875 Marin Dr (0.42 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)
Parcel & Assessor
- Lot size:
- 12,589 sq ft (0.29 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 534 MARIN 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 (Local Responsibility Area) (all of the lot, map Mar 24, 2025)
- 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: $1,947,000 – $2,477,000 · 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)0.42 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 560 Alta Way (Applied)0.36 mi N
In "Applied" for 3.3 yr (since Aug 10, 2023), 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, $975,000 declared valuation across 1 permit).
- Remodel / interior alteration (169226) (Issued)On this parcel
Issued after 14 mo (5.1× the 83d median) — slower than 90% of remodel / interior alteration permits in Unincorporated Marin (median 83d, 90th pct 266d, n=1,054).
- Other (86034) (Applied)On this parcel
Pending in review for 6.3 yr — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,560).
Entity-resolved builders & contractors in ½ mile: Tesla Energy (2 on parcel, 2 in ½ mi · Solar / battery storage); Sausalito Construction (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Earth Star Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Bellows Plumbing Heating And Air (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer); Owner Builder (76 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (6 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B28326 | Plumbing / water heater / sewer | Issued | Iss. Jan 12, 2022 | $3,500 | Replace existing failed power vent Bradford White 75G water heater with new, like for like. — Replace Plumbing Fixtures(… |
| 169226 | Remodel / interior alteration | Issued | Iss. Aug 30, 2021 | $18,000 | Convert Attic Above Garage To J.A.D.U. T.D. 8-13-20 *Ok To Extend 7/31/2022; Bc** |
| 86034 | Other | Applied | App. Jul 16, 2020 | — | ( |
| B22947 | Electrical / panel | Issued | Iss. Jul 7, 2020 | $4,700 | Electrical service upgrade (replacement) 200A like-for-like — Service Upgrade |
| 163905 | Solar / battery storage | Issued |