315 Hillside Ave
Mill Valley 94941 · Mill Valley · Coordinates: 37.91104, -122.54451
Parcel & Assessor
- Lot size:
- 5,445 sq ft (0.13 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 315 HILLSIDE AVE; 315 HILLSIDE 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 ADUPossible, with conditions
Zoned RS-6 (single-family residential): state law allows ADUs where homes are allowed. Very High Fire Hazard Severity Zone covers all of the lot: cities may limit ADUs here for fire safety and evacuation.
- SB 9: two homes on the lotPossible, with conditions
Zoned RS-6, a single-family residential zone. Very High Fire Hazard Severity Zone (local responsibility area) covers all of the lot: SB 9 requires the project to meet the fire hazard mitigation standards.
- SB 9: split into two lotsPossible, with conditions
Zoned RS-6, a single-family residential zone. The lot is 5,445 sq ft by the assessor, room for two lots of at least 1,200 sq ft, each at least 40% of the original. Very High Fire Hazard Severity Zone (local responsibility area) covers all of the lot: SB 9 requires the project to meet the fire hazard mitigation standards.
Mapped Hazard Zones on This Lot
- CAL FIRE Fire Hazard Severity Zone
- Very 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: $1,839,000 – $2,489,000 · 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)
14 active or recent development projects (18 housing units across completed, permitted, and pipeline stages) and 1 total building permits recorded within ½ mile.
- Other
Developments Deserving Closer Investigation & Active Area Builders
- Detached ADU (Issued)On this parcel
Active in "Issued" for 13 mo (first record Oct 1, 2025) with no new permit activity recorded in 13 mo.
- New home (Entitled)0.22 mi S
Active in "Entitled" for 6.1 yr (first record Sep 9, 2020) with no new permit activity recorded in 6.1 yr. High-impact scale (1 housing unit, 1 deed-restricted affordable across 0 permits).
- MFR/Office Overlay (Entitled)0.38 mi S
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).
- New home (Issued)0.11 mi SE
Active in "Issued" for 9.5 yr (first record Apr 17, 2017) with no new permit activity recorded in 9.5 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 2025).