20 Century Dr
Mill Valley 94941 · Strawberry · Unincorporated Marin · Coordinates: 37.87893, -122.49984
Executive Verdict · Public-Records Synthesis
Zoned RSP-5-BFC in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,338,000 ($2,057,000–$2,619,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned RSP-5-BFC supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 19,646 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$9,387 contributory est.)
Public building records show issued construction/renovation work on this parcel (7 total permits, latest Oct 4, 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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home at 7 Charles Van Damme Dock (0.45 mi SW, issued). 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 (~$27,337/yr at $2,338,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,278/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:
- 19,646 sq ft (0.45 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 20 CENTURY DR
Zoning & Land Use
RSP-5-BFC — Residential Single Family Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RSP-5-BFC (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned RSP-5-BFC, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned RSP-5-BFC, a single-family residential zone. The lot is 19,646 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 06041C0488E, 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: $2,057,000 – $2,619,000 · 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
- New home at 7 Charles Van Damme Dock (Issued)0.45 mi SW
Active in "Issued" for 9.3 yr (first record Aug 1, 2017) with no new permit activity recorded in 7.2 yr. High-impact scale (1 housing unit, 1 deed-restricted affordable, $110,000 declared valuation across 1 permit).
- New home (Entitled)0.22 mi N
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)0.25 mi N
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).
- New home at 61 Liberty Dock (Applied)0.37 mi S
In "Applied" for 11.5 yr (since May 6, 2015), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
Entity-resolved builders & contractors in ½ mile: Divine Electric (2 on parcel, 2 in ½ mi · Electrical / panel); Fast Water Heater (2 on parcel, 2 in ½ mi · Plumbing / water heater / sewer); Tesla Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Northern Pacific Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Wchs Operations (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer).
Permit & Project History on This Parcel (7 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B48630 | Plumbing / water heater / sewer | Issued | Iss. Oct 4, 2026 | $10,000 | Replace Plumbing Fixtures(s) |
| B46267 | Plumbing / water heater / sewer | Issued | Iss. Apr 8, 2026 | $3,081 | Replace Plumbing Fixtures(s) |
| 168750 | Solar / battery storage | Issued | Iss. Jul 7, 2021 | $26,075 | 8.16 Kw Rooftop Photovoltaic & Energy Storage System - Express |
| B24044 | Electrical / panel | Issued | Iss. Nov 2, 2020 | $6,000 | Replace existing 100A Main Service Panel with new 100A at original location. — Service Upgrade |
| B20455 | Electrical / panel | Issued | Iss. Nov 26, 2019 |