813 Descanso Way
San Rafael 94903 · Santa Venetia · Unincorporated Marin · Coordinates: 38.01635, -122.51408
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ministerial ADU eligibility and mapped FEMA AE flood due diligence; benchmark value $1,172,000 ($1,031,000–$1,313,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone R1-B1 allows residential use qualifying for ministerial ADU review under state law (2 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ 4 documented municipal building permits on file
On-parcel permit history is indexed through Sep 15, 2025, 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
- ! FEMA Special Flood Hazard Area (AE, all of the lot of lot)
Zone AE: 1% annual chance flood (Special Flood Hazard Area) overlaps this parcel. Expect mandatory flood insurance for federally backed loans and floodplain elevation/mitigation rules for new units or SB 9 applications.
Source: FEMA National Flood Hazard Layer (parcel polygon)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home at 35 Pt Gallinas Rd (0.38 mi E, 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 (~$13,928/yr at $1,172,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,161/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:
- 6,273 sq ft (0.14 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 813 DESCANSO WAY
Zoning & Land Use
R1-B1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotPossible, with conditions
Zoned R1-B1, a single-family residential zone. FEMA Special Flood Hazard Area (Zone AE) covers all of the lot: the project must meet the National Flood Insurance Program floodplain standards, or the lot needs a map revision.
- SB 9: split into two lotsPossible, with conditions
Zoned R1-B1, a single-family residential zone. The lot is 6,273 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original. FEMA Special Flood Hazard Area (Zone AE) covers all of the lot: the project must meet the National Flood Insurance Program floodplain standards, or the lot needs a map revision.
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 AE: 1% annual chance flood (Special Flood Hazard Area) (all of the lot) · FIRM panel 06041C0294E, 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: $1,031,000 – $1,313,000 · Status: Off market
HUD Small Area FMR (ZIP 94903) · FY 2026
Studio $2,880 · 1BR $3,450 · 2BR $4,180 · 3BR $5,340 · 4BR $5,530
Developments Deserving Closer Investigation & Active Area Builders
- New home at 35 Pt Gallinas Rd (Issued)0.38 mi E
Active in "Issued" for 9.5 yr (first record May 24, 2017) with no new permit activity recorded in 9.3 yr. High-impact scale (1 housing unit, $2,367,450 declared valuation across 1 permit).
- Accessory dwelling unit at 835 Rosal Way (Applied)300 ft E
In "Applied" for 2.2 yr (since Sep 11, 2024), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Accessory dwelling unit at 798 Hacienda Way (Applied)0.1 mi W
In "Applied" for 11.1 yr (since Oct 5, 2015), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121).
- Demolition at 1145 Adrian Way (Applied)0.25 mi SE
In "Applied" for 4.9 yr (since Dec 2, 2021), exceeding the 55d median and 261d 90th percentile for demolition permits in Unincorporated Marin (n=130).
Entity-resolved builders & contractors in ½ mile: Ken Cooper Roofing And Gutter (1 on parcel, 1 in ½ mi · Roof replacement); Morris Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Ongaro Ernest And Sons (1 on parcel, 1 in ½ mi · HVAC / heat pump); Ernest Ongaro And Sons (1 on parcel, 1 in ½ mi · HVAC / heat pump); Owner Builder (19 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (4 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B43874 | Roof replacement | Issued | Iss. Sep 15, 2025 | $29,000 | Remove Tar and Gravel roof and installed new Class A Material with double underlayment. Class A Leaf Screens. — ReRoofin… |
| B17846 | HVAC / heat pump | Issued | Iss. May 24, 2019 | $3,000 | Like for like change out of Furnace (Afue 81%) — Replace Mechanical Appliance |
| B10849 | Roof replacement | Issued | Iss. Aug 22, 2016 | $14,375 | REROOF — ReRoofing |
| 148033 | HVAC / heat pump | Issued | Iss. Jul 16, 2015 | $4,400 | Add A/C |