342 Pinehill Rd
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.88336, -122.53399
Executive Verdict · Public-Records Synthesis
Zoned R1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,260,000 ($1,989,000–$2,531,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 8,320 sq ft lot. Local precedent is active with 7 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$137,310 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest Sep 3, 2024).
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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home at 560 Alta Way (0.39 mi W, 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 (~$26,440/yr at $2,260,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,203/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:
- 8,320 sq ft (0.19 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 342 PINEHILL RD
Zoning & Land Use
R1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1, a single-family residential zone. The lot is 8,320 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
- 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 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: $1,989,000 – $2,531,000 · 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
Nearby Activity (½ mile radius, since November 2024)
30 active or recent development projects (28 housing units across completed, permitted, and pipeline stages) and 691 total building permits recorded within ½ mile.
- New construction14 permits (4 units)
- Adds housing (ADU)24 permits (24 units)
- Demolition2 permits
- Additions & renovations42 permits
- Building systems484 permits
- Repairs24 permits
- Other101 permits
Developments Deserving Closer Investigation & Active Area Builders
- New home at 560 Alta Way (Applied)0.39 mi W
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 217 Cleveland Ave (Issued)0.34 mi E
Active in "Issued" for 9.7 yr (first record Feb 21, 2017) with no new permit activity recorded in 2.3 yr. High-impact scale (1 housing unit, $875,000 declared valuation across 1 permit).
- New commercial building at 100 Harvard Ave (Issued)0.36 mi N
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).
- Accessory dwelling unit at 403 Marin Ave (adu 403a) (Issued)0.38 mi S
Active in "Issued" for 2.9 yr (first record Dec 21, 2023) with no new permit activity recorded in 19 mo. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Owner Builder (1 on parcel, 116 in ½ mi · Remodel / interior alteration); Ogarrio Wireless (1 on parcel, 1 in ½ mi · Solar / battery storage); Bellows Plumbing Heating And Air (1 on parcel, 1 in ½ mi · HVAC / heat pump); Maap (1 on parcel, 1 in ½ mi · Windows / doors / siding); Damran Electric (1 on parcel, 1 in ½ mi · Electrical / panel).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B39333 | Solar / battery storage | Issued | Iss. Sep 3, 2024 | $50,000 | Installation of Tesla Solar Roof V3R Photovoltaic system, with a Battery backups system Powerwall 3. |
| 175791 | Addition (adds square footage) | Issued | Iss. Jan 19, 2024 | $175,000 | Addition; Remodel: (2) Baths & Kitchen; Deck & Stairs @ Rear Yard |
| B27116 | Electrical / panel | Issued | Iss. Sep 22, 2021 | $5,000 | Replace 100AMP meter box with 200AMP meter box — Service Upgrade |
| B26600 | HVAC / heat pump | Issued | Iss. Aug 12, 2021 | $20,000 | Remove 2 existing gas furnaces and install new 5 ton Mitsubishi Heat Pump — Mechanical Appliance |
| B26233 | Windows / doors / siding | Issued | Iss. Jul 7, 2021 | $9,865 | Replace 10 windows in-kind with white vinyl - WUI glass — Non-structural Door/Window Replacement |