503 Headlands Ct
Sausalito 94965 · Marin City · Unincorporated Marin · Coordinates: 37.87795, -122.51970
Executive Verdict · Public-Records Synthesis
Zoned RMP-10 in Unincorporated Marin with likely ministerial ADU eligibility and mapped CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $1,533,000 ($1,349,000–$1,717,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-10 allows residential use qualifying for ministerial ADU review under state law.
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$13,454 contributory est.)
Public building records show issued construction/renovation work on this parcel (2 total permits, latest Sep 24, 2025).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Marin City
21 substantial renovation & housing permits over 24 months (40.5 per 1,000 parcels vs. 16.3 citywide baseline) (#14 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Marin City)
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 Moderate 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: 74 new homes at 825 Drake Ave (0.38 mi SE, 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 (~$18,080/yr at $1,533,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,507/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:
- 653 sq ft (0.01 ac)
- Assessor use:
- Single Family Attached
- Addresses on lot:
- 503 HEADLANDS CT
Zoning & Land Use
RMP-10 — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-10 (multifamily residential): state law allows ADUs where homes are allowed. On a multifamily lot the state allowance is different: ADUs in non-living space of the building, plus up to eight detached ADUs.
- SB 9: two homes on the lotUnlikely
Zoned RMP-10 (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-10 (multifamily residential), not a single-family residential zone.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Moderate 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 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: $1,349,000 – $1,717,000 · Status: Off market
HUD Small Area FMR (ZIP 94965) · FY 2026
Studio $2,720 · 1BR $3,260 · 2BR $3,950 · 3BR $5,050 · 4BR $5,230
Developments Deserving Closer Investigation & Active Area Builders
- 74 new homes at 825 Drake Ave (Issued)0.38 mi SE
Active in "Issued" for 6 yr (first record Nov 30, 2020) with no new permit activity recorded in 3.5 yr. High-impact scale (74 housing units, $8,731,920 declared valuation across 1 permit).
- New commercial building at 201 Flamingo Rd (aka 205) (Issued)0.41 mi NW
Active in "Issued" for 11.7 yr (first record Feb 17, 2015) with no new permit activity recorded in 11.2 yr. High-impact scale ($3,938,400 declared valuation across 3 permits).
- New home at 25 Burgess Ct (adu #23) (Issued)0.46 mi SE
Active in "Issued" for 6.9 yr (first record Dec 30, 2019) with no new permit activity recorded in 5.1 yr. High-impact scale (1 housing unit, $2,200,000 declared valuation across 1 permit).
- Demolition at 160 Shoreline Hwy - (Issued)0.26 mi N
Active in "Issued" for 6.7 yr (first record Feb 19, 2020) with no new permit activity recorded in 6.7 yr.
Entity-resolved builders & contractors in ½ mile: Bright Planet Solar (1 on parcel, 1 in ½ mi · Solar / battery storage); Golden Gate Home Improvement (1 on parcel, 1 in ½ mi · Windows / doors / siding); Owner Builder (32 in ½ mi · Remodel / interior alteration); Owner (25 in ½ mi · Remodel / interior alteration); Ga Higgins (22 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B44027 | Solar / battery storage | Issued | Iss. Sep 24, 2025 | $31,143 | Residential roof mount PV solar system; 11 modules; 4.455kW; with (1) solaredge ESS |
| B27164 | Windows / doors / siding | Issued | Iss. Sep 27, 2021 | $29,400 | Replace (4) sliding patio doors, same size as existing. — Non-structural Door/Window Replacement |