20 Poppy Ln
Mill Valley 94941 · Tamalpais · Unincorporated Marin · Coordinates: 37.88264, -122.53693
Executive Verdict · Public-Records Synthesis
Zoned RA-B2 in Unincorporated Marin with likely ministerial ADU eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,145,000 ($1,888,000–$2,402,000).
Upsides & Opportunities
- ✓ Ministerial ADU / JADU pathway likely eligible
Zone RA-B2 allows residential use qualifying for ministerial ADU review under state law (4 ADU permits permitted within ¼ mile in 36 months).
Source: Unincorporated Marin zoning · CA Gov. Code 66314
- ✓ 5 documented municipal building permits on file
On-parcel permit history is indexed through Jul 30, 2026, 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 Tamalpais
50 substantial renovation & housing permits over 24 months (20.5 per 1,000 parcels vs. 16.3 citywide baseline) (#3 of 22 neighborhoods).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (Tamalpais)
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)
- ! Delayed or open permit activity on this parcel
General repair (93038): Pending in review for 20 mo (7.3× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
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 560 Alta Way (0.28 mi NW, 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 (~$25,118/yr at $2,145,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,093/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:
- 9,540 sq ft (0.22 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 20 POPPY LN
Zoning & Land Use
RA-B2 — Residential Agriculture (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RA-B2 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotCan't tell
Zoned RA-B2 (single-family residential): we can't tell whether it counts as a single-family zone for SB 9. Residential agriculture, estate and restricted: large-lot residential; confirm SB 9 with the county.
- SB 9: split into two lotsCan't tell
Zoned RA-B2 (single-family residential): we can't tell whether it counts as a single-family zone for SB 9. Residential agriculture, estate and restricted: large-lot residential; confirm SB 9 with the county.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Not in a State-mapped fire hazard severity zone
- 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: $1,888,000 – $2,402,000 · 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
Nearby Activity (½ mile radius, since November 2024)
26 active or recent development projects (25 housing units across completed, permitted, and pipeline stages) and 617 total building permits recorded within ½ mile.
- New construction10 permits (4 units)
- Adds housing (ADU)22 permits (22 units)
- Demolition1 permit
- Additions & renovations31 permits
- Building systems433 permits
- Repairs23 permits
- Other97 permits
Developments Deserving Closer Investigation & Active Area Builders
- New home at 560 Alta Way (Applied)0.28 mi NW
In "Applied" for 3.3 yr (since Aug 10, 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, $975,000 declared valuation across 1 permit).
- General repair (93038) (Applied)On this parcel
Pending in review for 20 mo (7.3× the 83d median) — slower than 90% of general repair permits in Unincorporated Marin (median 83d, 90th pct 328d, n=693).
- Accessory dwelling unit at 403 Marin Ave (adu 403a) (Issued)0.33 mi S
Active in "Issued" for 2.9 yr (first record Dec 21, 2023) with no new permit activity recorded in 19 mo. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
- New home at 731 Bay Rd (Issued)0.34 mi SW
Active in "Issued" for 18 mo (first record May 12, 2025) with no new permit activity recorded in 15 mo. High-impact scale (1 housing unit, $955,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Apollo Building And Roofing Group (1 on parcel, 1 in ½ mi · Roof replacement); First Impressions Painting And Building (1 on parcel, 1 in ½ mi · Remodel / interior alteration); J And J Electric (1 on parcel, 1 in ½ mi · Other); Grupe HVAC (1 on parcel, 1 in ½ mi · HVAC / heat pump); Owner Builder (101 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B47692 | Roof replacement | Issued | Iss. Jul 30, 2026 | $41,000 | ReRoofing |
| 93038 | General repair | Applied | App. Mar 17, 2025 | $10,000 | Replace (E) Retaining Wall In Parking Area |
| B27325 | HVAC / heat pump | Issued | Iss. Oct 6, 2021 | $10,700 | Replaced the Air Conditioning Unit — Replace Mechanical Appliance |
| B26586 | Other | Issued | Iss. Aug 10, 2021 | $18,000 | Provide and install 20kw generator and auto transfer switch. |
| 141133 | Remodel / interior alteration | Issued | Iss. Jan 8, 2014 | $25,000 | Rmdl Kit; Extend Deck T.D. 12/26/13 ***Extend Permit Until 1/8/2017 Per Bk*** Expired |