1435 Butterfield Rd
San Anselmo 94960 · Sleepy Hollow · Unincorporated Marin · Coordinates: 38.01493, -122.58637
Executive Verdict · Public-Records Synthesis
Zoned RMP-0.1 in Unincorporated Marin with likely ministerial ADU eligibility and mapped CAL FIRE moderate fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,220,000 ($1,954,000–$2,486,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RMP-0.1 allows residential use qualifying for ministerial ADU review under state law (1 ADU permit permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ Documented permitted upgrades (+$223,674 contributory est.)
Public building records show issued construction/renovation work on this parcel (8 total permits, latest Mar 3, 2026).
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. 16.4 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)
- ! Delayed or open permit activity on this parcel
Other (181204): Issued after 3 mo — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,560).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 5 slow or stalled nearby projects within ½ mile
Closest lead: New home at 99 Garden Rock Rd (0.37 mi W, 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)
Parcel & Assessor
- Lot size:
- 56,672 sq ft (1.30 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 1435 BUTTERFIELD RD
Zoning & Land Use
RMP-0.1 — Residential Multiple Planned (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RMP-0.1 (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-0.1 (multifamily residential), not a single-family residential zone.
- SB 9: split into two lotsUnlikely
Zoned RMP-0.1 (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 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: $1,954,000 – $2,486,000 · 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
Developments Deserving Closer Investigation & Active Area Builders
- New home at 99 Garden Rock Rd (Applied)0.37 mi W
In "Applied" for 3.1 yr (since Oct 11, 2023), 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, $1,200,000 declared valuation across 1 permit).
- Other (181204) (Issued)On this parcel
Issued after 3 mo — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,560).
- New commercial building at 1500 Butterfield Rd (Issued)0.13 mi N
Active in "Issued" for 4 yr (first record Oct 25, 2022) with no new permit activity recorded in 12 mo. High-impact scale ($2,700,000 declared valuation across 2 permits).
- New commercial building at 1500 Butterfield Rd (Applied)0.13 mi N
Active in "Applied" for 7.5 yr (first record May 15, 2019) with no new permit activity recorded in 7.5 yr. High-impact scale ($2,500,000 declared valuation across 2 permits).
Entity-resolved builders & contractors in ½ mile: Owner (1 on parcel, 13 in ½ mi · New garage / accessory structure); K Kinahan Construction (2 on parcel, 2 in ½ mi · Addition (adds square footage)); Solar Technologies (1 on parcel, 1 in ½ mi · Solar / battery storage); Ken Cooper Roofing And Gutter (1 on parcel, 1 in ½ mi · Roof replacement); J And J Electric (1 on parcel, 1 in ½ mi · Solar / battery storage).
Permit & Project History on This Parcel (8 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 181204 | Other | Issued | Iss. Mar 3, 2026 | $27,000 | Raise Fence Height |
| 177526 | Addition (adds square footage) | Issued | Iss. Sep 6, 2024 | $930,000 | Remodel & Addition; Decks; Windows; Siding |
| B38490 | Windows / doors / siding | Issued | Iss. Jun 21, 2024 | $5,000 | removal of wood siding for exploratory look for water damage and window repair — Siding Replacement |
| B34305 | Plumbing / water heater / sewer | Issued | Iss. Jun 15, 2023 | $4,670 | Install 40 gallon water heater in existing location — Replace Plumbing Fixtures(s) |
| 173204 | Solar / battery storage | Issued | Iss. Jan 17, 2023 |