25 Sidney St
Mill Valley 94941 · Mill Valley · Coordinates: 37.90521, -122.53682
Parcel & Assessor
- Lot size:
- 6,447 sq ft (0.15 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 25 SIDNEY ST; 25 SIDNEY ST 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 6,447 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 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: $1,865,000 – $2,523,000 · 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)
18 active or recent development projects (18 housing units across completed, permitted, and pipeline stages) and 3 total building permits recorded within ½ mile.
- Other
Developments Deserving Closer Investigation & Active Area Builders
- Conversion detached structure (Issued)On this parcel
Active in "Issued" for 5.9 yr (first record Dec 18, 2020) with no new permit activity recorded in 5.9 yr.
- 25 new homes (Entitled)0.5 mi SE
Active in "Entitled" for 3.5 yr (first record May 6, 2023) with no new permit activity recorded in 3.5 yr. High-impact scale (25 housing units, 6 deed-restricted affordable across 0 permits).
- Detached ADU (Issued)250 ft SW
Active in "Issued" for 16 mo (first record Jun 17, 2025) with no new permit activity recorded in 16 mo.
- New home (Issued)0.11 mi SE
Active in "Issued" for 4.7 yr (first record Feb 14, 2022) with no new permit activity recorded in 3.8 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: 1 entry (report years 2020).