409 Throckmorton Ave
Mill Valley 94941 · Mill Valley · Coordinates: 37.90673, -122.55522
Parcel & Assessor
- Lot size:
- 5,097 sq ft (0.12 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 409 THROCKMORTON AVE; 409 THROCKMORTON AVE UNIT A
Zoning & Land Use
RS-6 — Single Fam Res (min 6,000 SF) (Mill Valley)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RS-6 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned RS-6, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned RS-6, a single-family residential zone. The lot is 5,097 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 (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 06041C0466F, 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: $1,830,000 – $2,476,000 · 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 October 2024)
12 active or recent development projects (16 housing units across completed, permitted, and pipeline stages) and 25 total building permits recorded within ½ mile.
Developments Deserving Closer Investigation & Active Area Builders
- MFR/Office Overlay (Entitled)0.47 mi E
Active in "Entitled" for 13 mo (first record Oct 13, 2025) with no new permit activity recorded in 13 mo. High-impact scale (5 housing units across 0 permits).
- Attached ADU (Entitled)330 ft NE
Active in "Entitled" for 3.9 yr (first record Dec 22, 2022) with no new permit activity recorded in 3.9 yr.
- Convert Unconditioned (Issued)0.14 mi NE
Active in "Issued" for 2.6 yr (first record Mar 28, 2024) with no new permit activity recorded in 2.6 yr.
- New home (Issued)0.14 mi NW
Active in "Issued" for 8.2 yr (first record Aug 28, 2018) with no new permit activity recorded in 8.2 yr.
Permit & Project History on This Parcel (0 permits, 1 grouped projects)
No building permits recorded on this parcel in our dataset.
State HCD Housing Element APR records on this parcel: 2 entries (report years 2024, 2025).