1170 Butterfield Rd
San Anselmo 94960 · Sleepy Hollow · Unincorporated Marin · Coordinates: 38.00950, -122.58112
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 $2,072,000 ($1,823,000–$2,321,000).
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 27,051 sq ft lot. Local precedent is active with 2 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$75,460 contributory est.)
Public building records show issued construction/renovation work on this parcel (13 total permits, latest Dec 20, 2023).
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
Addition (adds square footage) (175650): Issued after 2.3 yr (5.2× the 160d median) — slower than 90% of addition (adds square footage) permits in Unincorporated Marin (median 160d, 90th pct 440d, n=316).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (review-time benchmark)
- ! 1 slow or stalled nearby project within ½ mile
Closest lead: New home at 40 De Burgh Dr (0.24 mi SW, 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:
- 27,051 sq ft (0.62 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 1170 BUTTERFIELD RD
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 27,051 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: $1,823,000 – $2,321,000 · 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 40 De Burgh Dr (Applied)0.24 mi SW
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).
- Addition (adds square footage) (175650) (Issued)On this parcel
Issued after 2.3 yr (5.2× the 160d median) — slower than 90% of addition (adds square footage) permits in Unincorporated Marin (median 160d, 90th pct 440d, n=316).
- New garage / accessory structure (175649) (Issued)On this parcel
Issued after 4.4 yr (9.7× the 164d median) — slower than 90% of new garage / accessory structure permits in Unincorporated Marin (median 164d, 90th pct 485d, n=356).
- Other (88899) (Applied)On this parcel
Pending in review for 5.2 yr — slower than 90% of other permits in Unincorporated Marin (median 0d, 90th pct 71d, n=1,560).
Entity-resolved builders & contractors in ½ mile: Mark Mohtashem Construction (7 on parcel, 7 in ½ mi · Electrical / panel); Solarcraft Services (1 on parcel, 1 in ½ mi · Solar / battery storage); Tesla Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Dickson (1 on parcel, 1 in ½ mi · HVAC / heat pump); Earth Star Electric (1 on parcel, 1 in ½ mi · Electrical / panel).
Permit & Project History on This Parcel (13 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 175650 | Addition (adds square footage) | Issued | Iss. Dec 20, 2023 | $85,000 | Remod & Addtn To Family Room T U S C **Extended To 10/1/24.Nh.Lw** |
| 175649 | New garage / accessory structure | Issued | Iss. Dec 20, 2023 | $80,000 | New Accsry Struc - Exercise/Storage Bldg, Unconditioned |
| 88899 | Other | Applied | App. Sep 8, 2021 | $85,000 | Addition To Family Room Of A S. F. R |
| 88898 | Other | Applied | App. Sep 8, 2021 | $85,000 | Addition To Family Room Of A S. F. R |
| B26711 | Electrical / panel | Issued | Iss. Aug 23, 2021 | $4,700 |