166 Great Circle Dr
Mill Valley 94941 · Strawberry · Unincorporated Marin · Coordinates: 37.88217, -122.50081
Executive Verdict · Public-Records Synthesis
Zoned RSP-5 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,449,000 ($2,155,000–$2,743,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned RSP-5 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 17,729 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$138,000 contributory est.)
Public building records show issued construction/renovation work on this parcel (4 total permits, latest Jun 23, 2026).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Strawberry
43 substantial renovation & housing permits over 24 months (28.4 per 1,000 parcels vs. 16.4 citywide baseline) (#1 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Strawberry)
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)
- ! Delayed or open permit activity on this parcel
Electrical / panel (94322): Pending in review for 5 mo — slower than 90% of electrical / panel permits in Unincorporated Marin (median 0d, 90th pct 2d, n=3,019).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 5 slow or stalled nearby projects within ½ mile
Closest lead: New home (80 ft SW, entitled). 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 (~$28,614/yr at $2,449,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,384/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:
- 17,729 sq ft (0.41 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 166 GREAT CIRCLE DR
Zoning & Land Use
RSP-5 — Residential Single Family Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RSP-5 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned RSP-5, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned RSP-5, a single-family residential zone. The lot is 17,729 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 06041C0469F, 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: $2,155,000 – $2,743,000 · 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
- Electrical / panel (94322) (Applied)On this parcel
Pending in review for 5 mo — slower than 90% of electrical / panel permits in Unincorporated Marin (median 0d, 90th pct 2d, n=3,019).
- New home (Entitled)80 ft SW
In "Entitled" for 5.1 yr (since Sep 30, 2021), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Demolition at 171 Great Cir Dr (Applied)210 ft W
In "Applied" for 15 mo (since Aug 14, 2025), exceeding the 55d median and 261d 90th percentile for demolition permits in Unincorporated Marin (n=130).
- Demolition at 129 Great Cir Dr (Issued)0.11 mi SE
Active in "Issued" for 6.6 yr (first record Apr 1, 2020) with no new permit activity recorded in 6.5 yr.
Entity-resolved builders & contractors in ½ mile: Owner Builder (1 on parcel, 20 in ½ mi · Remodel / interior alteration); Piscatelli (1 on parcel, 1 in ½ mi · Roof replacement); Schneur Scop (1 on parcel, 1 in ½ mi · Electrical / panel); Lek Enterprises (35 in ½ mi · Remodel / interior alteration); Owner (11 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (4 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 94322 | Electrical / panel | Applied | App. Jun 23, 2026 | $60,000 | New Fence, Pedestrian Gate, Automatic Driveway Gate, Retaining Wall, Pathway To Front Door, Topcoat On Driveway |
| B44104 | Electrical / panel | Issued | Iss. Oct 9, 2025 | $12,000 | PG&E Service Upgrade from 100 amps to 320 amps. — Service Upgrade |
| B43822 | Roof replacement | Issued | Iss. Sep 10, 2025 | $85,000 | tear-off existing roof, install Taylor Metal Standing Seam Metal Roof 4100 Sq ft — ReRoofing |
| 177999 | Remodel / interior alteration | Issued | Iss. Nov 1, 2024 | $900,000 | Interior Remodel; Replacing Windows & Doors; Expanding (E) Decks |