701 Alta Vista Rd
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.87881, -122.54322
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,136,000 ($1,880,000–$2,392,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 7,405 sq ft lot. Local precedent is active with 5 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$33,000 contributory est.)
Public building records show issued construction/renovation work on this parcel (3 total permits, latest Aug 15, 2023).
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 (0.3 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 (~$25,014/yr at $2,136,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,085/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:
- 7,405 sq ft (0.17 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 701 ALTA VISTA RD
Zoning & Land Use
R1-B1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B1, a single-family residential zone. The lot is 7,405 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original.
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: $1,880,000 – $2,392,000 · 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)0.3 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)0.48 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).
- New home at 731 Bay Rd (Issued)0.14 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).
- New home at 760 Bay Rd (Issued)0.16 mi SE
Active in "Issued" for 9.4 yr (first record Jun 12, 2017) with no new permit activity recorded in 8.4 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, 67 in ½ mi · Remodel / interior alteration); Builders Of Marin (2 on parcel, 2 in ½ mi · Other); Owner (28 in ½ mi · Remodel / interior alteration); International Building Investment (12 in ½ mi · Remodel / interior alteration); Leon Construction (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 |
|---|---|---|---|---|---|
| 174761 | Addition (adds square footage) | Issued | Iss. Aug 15, 2023 | $50,000 | Upper Level Addition For Closet |
| 149044 | Other | Issued | Iss. Sep 21, 2015 | $15,000 | Replace Decks T.D. 9/10/15 |
| 145340 | Remodel / interior alteration | Issued | Iss. Dec 30, 2014 | $200,000 | Interior Remodel T.D. 12/29/14 |