100 Auburn St
San Rafael 94901 · California Park · Unincorporated Marin · Coordinates: 37.95963, -122.51264
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 $1,385,000 ($1,219,000–$1,551,000).
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 8,189 sq ft lot. Local precedent is active with 3 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ 4 documented municipal building permits on file
On-parcel permit history is indexed through Feb 9, 2026, letting you verify roof, HVAC, electrical, or structural work against seller disclosures.
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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: 79 new homes at 0 Auburn St & Woodland Ave (450 ft SE, 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 (~$16,378/yr at $1,385,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,365/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:
- 8,189 sq ft (0.19 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 100 AUBURN ST
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 8,189 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 06041C0459F, 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: $1,219,000 – $1,551,000 · Status: Off market
HUD Small Area FMR (ZIP 94901) · FY 2026
Studio $2,150 · 1BR $2,580 · 2BR $3,120 · 3BR $3,990 · 4BR $4,130
Nearby Activity (½ mile radius, since November 2024)
8 active or recent development projects (85 housing units across completed, permitted, and pipeline stages) and 63 total building permits recorded within ½ mile.
- New construction18 permits
- Adds housing (ADU)5 permits (5 units)
- Additions & renovations6 permits
- Building systems23 permits
- Repairs3 permits
- Other8 permits
Developments Deserving Closer Investigation & Active Area Builders
- 79 new homes at 0 Auburn St & Woodland Ave (Applied)450 ft SE
In "Applied" for 23 mo (since Dec 18, 2024), exceeding the 292d median and 313d 90th percentile for new multifamily / condos / mixed-use permits in Unincorporated Marin (n=21). High-impact scale (79 housing units, 16 deed-restricted affordable across 16 permits).
- 71 new homes (Entitled)0.4 mi NE
In "Entitled" for 4.5 yr (since May 10, 2022), exceeding the 292d median and 313d 90th percentile for new multifamily / condos / mixed-use permits in Unincorporated Marin (n=21). High-impact scale (71 housing units, 6 deed-restricted affordable across 0 permits).
- 32 new homes (Issued)0.47 mi N
Active in "Issued" for 6.6 yr (first record Apr 6, 2020) with no new permit activity recorded in 5.8 yr. High-impact scale (32 housing units across 0 permits).
- New home (Entitled)430 ft W
In "Entitled" for 6.2 yr (since Sep 11, 2020), 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: Byron Smith General Contractor (1 on parcel, 1 in ½ mi · Remodel / interior alteration); Wedge Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Drive Technologies (1 on parcel, 1 in ½ mi · EV charger); Kelly Plumbing And Heating (1 on parcel, 1 in ½ mi · Other); Owner Builder (14 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (4 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B45806 | Other | Issued | Iss. Feb 9, 2026 | $4,500 | Replace Mechanical Appliance |
| B36205 | EV charger | Issued | Iss. Nov 26, 2023 | $8,000 | Utility upgrade to 200A panel and installation of EV charger (Hardwired 48A Pulsar Plus) — Service Upgrade, EV Charging … |
| B24937 | Roof replacement | Issued | Iss. Feb 22, 2021 | $14,270 | Prepare existing 17 sq ft surface to receive new roof system. Apply 1 SPF with Silicone coating. — ReRoofing; With Elect… |
| 149079 | Remodel / interior alteration | Issued | Iss. Sep 22, 2015 | $60,000 | Kitchen Remodel T.D. 9/14/15 |