21 Catskill Ct
San Anselmo 94960 · Sleepy Hollow · Unincorporated Marin · Coordinates: 38.00963, -122.58506
Executive Verdict · Public-Records Synthesis
Zoned R1-BD in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $1,943,000 ($1,710,000–$2,176,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-BD supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 17,163 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
- ✓ 2 documented municipal building permits on file
On-parcel permit history is indexed through Jul 17, 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)
- ✓ Above-average reinvestment in Sleepy Hollow
32 substantial renovation & housing permits over 24 months (32.7 per 1,000 parcels vs. 16.3 citywide baseline) (#4 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Sleepy Hollow)
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: New home at 40 De Burgh Dr (0.18 mi S, 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 (~$22,795/yr at $1,943,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,900/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:
- 17,163 sq ft (0.39 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 21 CATSKILL CT
Zoning & Land Use
R1-BD — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-BD (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-BD, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-BD, a single-family residential zone. The lot is 17,163 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
- 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 06041C0289D, effective May 4, 2009
- CGS Alquist-Priolo Earthquake Fault Zone
- Not in an Alquist-Priolo Earthquake Fault Zone
Surrounding Rent & Value Benchmarks (Public Records)
Range: $1,710,000 – $2,176,000 · Status: Off market
HUD Small Area FMR (ZIP 94960) · FY 2026
Studio $2,510 · 1BR $3,010 · 2BR $3,640 · 3BR $4,650 · 4BR $4,820
Nearby Activity (½ mile radius, since November 2024)
2 active or recent development projects (1 housing units across completed, permitted, and pipeline stages) and 280 total building permits recorded within ½ mile.
- New construction7 permits
- Adds housing (ADU)1 permit (1 units)
- Demolition1 permit
- Additions & renovations24 permits
- Building systems201 permits
- Repairs13 permits
- Other33 permits
Developments Deserving Closer Investigation & Active Area Builders
- New home at 40 De Burgh Dr (Applied)0.18 mi S
In "Applied" for 9.3 yr (since Jul 31, 2017), exceeding the 253d median and 686d 90th percentile for new single-family home permits in Unincorporated Marin (n=121). High-impact scale (1 housing unit, $1,800,000 declared valuation across 3 permits).
- New commercial building at 1317 Butterfield Rd (Applied)360 ft N
Active in "Applied" for 10.5 yr (first record May 2, 2016) with no new permit activity recorded in 10.5 yr. High-impact scale ($2,500,000 declared valuation across 2 permits).
- New home at 121 Van Tassel Ct (Issued)0.2 mi N
Active in "Issued" for 8.7 yr (first record Feb 21, 2018) with no new permit activity recorded in 8.4 yr. High-impact scale (1 housing unit, $800,000 declared valuation across 1 permit).
- New commercial building at 1500 Butterfield Rd (Issued)0.49 mi N
Active in "Issued" for 4.1 yr (first record Oct 25, 2022) with no new permit activity recorded in 13 mo. High-impact scale ($2,700,000 declared valuation across 2 permits).
Entity-resolved builders & contractors in ½ mile: Adriano Silva (1 on parcel, 1 in ½ mi · Roof replacement); Integrity Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (33 in ½ mi · Remodel / interior alteration); Owner (18 in ½ mi · Remodel / interior alteration); Fisher Development (4 in ½ mi · Commercial tenant improvement).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B43086 | Roof replacement | Issued | Iss. Jul 17, 2025 | $31,500 | Reroofing. Tear off the 01 layer of the existing and install shingle — ReRoofing |
| 147227 | Electrical / panel | Issued | Iss. May 21, 2015 | $1,675 | Add Ext Subpanel 125 A; Car Charger Receptacle |