21 Madrone Park Cir
Mill Valley 94941 · Homestead · Unincorporated Marin · Coordinates: 37.89320, -122.54684
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and mapped CAL FIRE high fire hazard severity zone (state responsibility area) due diligence; benchmark value $2,028,000 ($1,785,000–$2,271,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 3,354 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
- ✓ 2 documented municipal building permits on file
On-parcel permit history is indexed through Jul 15, 2021, 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 Homestead
22 substantial renovation & housing permits over 24 months (20.7 per 1,000 parcels vs. 16.4 citywide baseline) (#2 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Homestead)
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 High 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 322 Laverne Ave (0.22 mi NE, 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 (~$23,772/yr at $2,028,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$1,981/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:
- 3,354 sq ft (0.08 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 21 MADRONE PARK CIR
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 lotLikely eligible
Zoned R1-B1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B1, a single-family residential zone. The lot is 3,354 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
- High 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 06041C0468F, 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: $1,785,000 – $2,271,000 · 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 322 Laverne Ave (Issued)0.22 mi NE
Active in "Issued" for 10 yr (first record Nov 10, 2016) with no new permit activity recorded in 9.4 yr. High-impact scale (1 housing unit, $800,000 declared valuation across 1 permit).
- New home at 346 Laverne Ave (Issued)0.23 mi N
Active in "Issued" for 10.7 yr (first record Mar 7, 2016) with no new permit activity recorded in 10.2 yr. High-impact scale (1 housing unit, $900,000 declared valuation across 2 permits).
- New home at 306 Holly St (Issued)0.27 mi N
Active in "Issued" for 8.1 yr (first record Sep 19, 2018) with no new permit activity recorded in 7.6 yr. High-impact scale (1 housing unit, $870,000 declared valuation across 1 permit).
- New home at 230 Laverne Ave (Issued)0.28 mi NE
Active in "Issued" for 11.7 yr (first record Mar 9, 2015) with no new permit activity recorded in 11.4 yr. High-impact scale (1 housing unit, $780,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: The Home Doctors (2 on parcel, 2 in ½ mi · General repair); Owner Builder (55 in ½ mi · Remodel / interior alteration); Owner (27 in ½ mi · Remodel / interior alteration); Foley Built (5 in ½ mi · Addition (adds square footage)); Spellbound Construction (4 in ½ mi · Addition (adds square footage)).
Permit & Project History on This Parcel (2 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 168828 | General repair | Issued | Iss. Jul 15, 2021 | $45,000 | Replc Retaining Wall (Related To Permit 166624) T.D. 6/23/21 |
| 166624 | Other | Issued | Iss. Dec 17, 2020 | $45,000 | Re-Build Existing Deck Related To Tracking # 88090 |