21 Eagle Rock Rd
Mill Valley 94941 · Strawberry · Unincorporated Marin · Coordinates: 37.90425, -122.51161
Executive Verdict · Public-Records Synthesis
Zoned R1-B2 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (local responsibility area) due diligence; benchmark value $2,226,000 ($1,959,000–$2,493,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B2 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 10,280 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 (+$7,680 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest Oct 2, 2026).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
- ✓ Above-average reinvestment in Strawberry
43 substantial renovation & housing permits over 24 months (28.4 per 1,000 parcels vs. 16.4 citywide baseline) (#1 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Strawberry)
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 (Local 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 Mar 24, 2025)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: New home at 55 Thomas Dr (0.1 mi N, 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 (~$26,049/yr at $2,226,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,171/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:
- 10,280 sq ft (0.24 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 21 EAGLE ROCK RD
Zoning & Land Use
R1-B2 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B2 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B2, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B2, a single-family residential zone. The lot is 10,280 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 (Local Responsibility Area) (all of the lot, map Mar 24, 2025)
- FEMA National Flood Hazard Layer
- Zone X: minimal flood hazard (all of the lot) · FIRM panel 06041C0469F, 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: $1,959,000 – $2,493,000 · Status: Off market
HUD Small Area FMR (ZIP 94941) · FY 2026
Studio $2,730 · 1BR $3,270 · 2BR $3,960 · 3BR $5,060 · 4BR $5,240
Developments Deserving Closer Investigation & Active Area Builders
- New home at 55 Thomas Dr (Applied)0.1 mi N
In "Applied" for 6.2 yr (since Sep 1, 2020), 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, $1,000,000 declared valuation across 1 permit).
- New home at 55 S Knoll Rd (Issued)0.25 mi S
Active in "Issued" for 11.9 yr (first record Dec 22, 2014) with no new permit activity recorded in 11.4 yr. High-impact scale (1 housing unit, $750,000 declared valuation across 1 permit).
- New home at 9 Sky Rd (Issued)0.3 mi SE
Active in "Issued" for 12.4 yr (first record Jun 23, 2014) with no new permit activity recorded in 11.6 yr. High-impact scale (1 housing unit, $1,200,000 declared valuation across 1 permit).
- Accessory dwelling unit at 55 Plaza Dr (adu 55a) (Issued)0.34 mi W
Active in "Issued" for 2.6 yr (first record Apr 17, 2024) with no new permit activity recorded in 19 mo. High-impact scale (1 housing unit, $790,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Sustainable Living Builders (1 on parcel, 1 in ½ mi · Roof replacement); Miltenberger Construction (1 on parcel, 1 in ½ mi · Electrical / panel); Maap (1 on parcel, 1 in ½ mi · Windows / doors / siding); Gaf Energy (1 on parcel, 1 in ½ mi · Solar / battery storage); Ernest Ongaro And Sons (1 on parcel, 1 in ½ mi · Plumbing / water heater / sewer).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B48623 | Plumbing / water heater / sewer | Issued | Iss. Oct 2, 2026 | $4,173 | Replace Plumbing Fixtures(s) |
| B44411 | Solar / battery storage | Issued | Iss. Oct 16, 2025 | $11,459 | Installation of a 2.392 kW BIPV solar shingle system. Breaker tie-in. ESS included. |
| B44181 | Roof replacement | Issued | Iss. Oct 3, 2025 | $89,950 | Re-roof. Removing existing wood shake shingles, re-sheathing and installing 39 squares of GAF Asphalt and Energy Shingle… |
| B36233 | Electrical / panel | Issued | Iss. Nov 27, 2023 | $58,800 | Replace kitchen cabinets, countertops & flooring. Replace one kitchen window, frame one exterior doorway from kitchen to… |
| B14589 | Windows / doors / siding |