Parcel Context · Public-Records Property BriefAPN 018-163-09

8 Main St

San Quentin 94964 · San Quentin · Unincorporated Marin · Coordinates: 37.94233, -122.48177

Executive Verdict · Public-Records Synthesis

Zoned RSP-5.8 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $1,436,000 ($1,221,000–$1,651,000).

Upsides & Opportunities

✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned RSP-5.8 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 8,930 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
✓ Documented permitted upgrades (+$7,360 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest Mar 11, 2025).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)

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)
! 1 slow or stalled nearby project within ½ mile
Closest lead: New home at 22 Mckenzie St (0.1 mi W, 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 (~$16,964/yr at $1,436,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,414/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:: 8,930 sq ft (0.21 ac)
Assessor use:: Single-Resid. - Improved
Addresses on lot:: 8 MAIN ST

Zoning & Land Use

RSP-5.8 — Residential Single Family Planned (Unincorporated Marin)

State Housing Pathways Screen (ADU & SB 9)

ADU or junior ADULikely eligible
Zoned RSP-5.8 (single-family residential): state law allows ADUs where homes are allowed.
SB 9: two homes on the lotLikely eligible
Zoned RSP-5.8, a single-family residential zone.
SB 9: split into two lotsLikely eligible
Zoned RSP-5.8, a single-family residential zone. The lot is 8,930 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 06041C0478E, effective March 16, 2016
CGS Alquist-Priolo Earthquake Fault Zone: Not in an Alquist-Priolo Earthquake Fault Zone

Surrounding Rent & Value Benchmarks (Public Records)

Estimated Price (Area ZHVI + ACS + Permit Benchmark):$1,436,000

Range: $1,221,000 – $1,651,000 · Status: Off market

HUD Small Area FMR (ZIP 94964) · FY 2026

Studio $2,530 · 1BR $3,040 · 2BR $3,680 · 3BR $4,700 · 4BR $4,870

ACS 2020–2024 Median Gross Rent (San Quentin):$3,500+

ACS 2020–2024 Median Home Value (San Quentin):$1,385,000±$160,000

Nearby Activity (½ mile radius, since November 2024)

0 active or recent development projects and 12 total building permits recorded within ½ mile.

Additions & renovations2 permits
Building systems8 permits

Developments Deserving Closer Investigation & Active Area Builders

New home at 22 Mckenzie St (Issued)0.1 mi W
Active in "Issued" for 3.9 yr (first record Dec 27, 2022) with no new permit activity recorded in 2.8 yr. High-impact scale (1 housing unit, $850,000 declared valuation across 1 permit).

Entity-resolved builders & contractors in ½ mile: Jemico (2 on parcel, 2 in ½ mi · Windows / doors / siding); Tesla Energy Operations (1 on parcel, 1 in ½ mi · Solar / battery storage); Divine Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Baldwin Electric (1 on parcel, 1 in ½ mi · Electrical / panel); James Flanagan Builder (2 in ½ mi · New garage / accessory structure).

Permit & Project History on This Parcel (5 permits, 0 grouped projects)

Record #	Category	Status	Applied / Issued	Valuation	Description
B41566	Windows / doors / siding	Issued	Iss. Mar 11, 2025	$3,332	Replace 1 full frame window and 1 entry door — Non-structural Door/Window Replacement
B38108	Solar / battery storage	Issued	Iss. May 22, 2024	$14,000	install 2 battery backups
B37995	Electrical / panel	Issued	Iss. May 9, 2024	$4,500	Upgrading from 100 AMP main panel to 200 AMP main panel. — Service Upgrade
B32440	Windows / doors / siding	Issued	Iss. Jan 31, 2023	$40,205	Replace 1 retrofit window and 3 full frame/nail fin ProVia entry doors — Non-structural Door/Window Replacement
B15175	Electrical / panel	Issued

Executive Verdict · Public-Records Synthesis

Zoned RSP-5.8 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $1,436,000 ($1,221,000–$1,651,000).

Upsides & Opportunities

✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned RSP-5.8 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 8,930 sq ft lot.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
✓ Documented permitted upgrades (+$7,360 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest Mar 11, 2025).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)

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)
! 1 slow or stalled nearby project within ½ mile
Closest lead: New home at 22 Mckenzie St (0.1 mi W, 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 (~$16,964/yr at $1,436,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,414/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector

State Housing Pathways Screen (ADU & SB 9)

ADU or junior ADULikely eligible

Zoned RSP-5.8 (single-family residential): state law allows ADUs where homes are allowed.

SB 9: two homes on the lotLikely eligible

Zoned RSP-5.8, a single-family residential zone.

SB 9: split into two lotsLikely eligible

Zoned RSP-5.8, a single-family residential zone. The lot is 8,930 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original.