5 Rainbow Ln
Mill Valley 94941 · Mill Valley · Coordinates: 37.90136, -122.54362
Executive Verdict · Public-Records Synthesis
Zoned RS-7.5 in Mill Valley with likely ADU & SB 9 infill eligibility and mapped CAL FIRE moderate fire hazard severity zone (local responsibility area) due diligence; benchmark value $2,240,000 ($1,904,000–$2,576,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned RS-7.5 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 8,407 sq ft lot.
Source: Mill Valley zoning · CA Gov. Code 66314 & 65852.21
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 Moderate Fire Hazard Severity Zone (Local 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 Mar 24, 2025)
- ! Delayed or open permit activity on this parcel
New home: Active in "Entitled" for 3.2 yr (first record Sep 3, 2023) with no new permit activity recorded in 3.2 yr.
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: MFR/Office Overlay (0.35 mi NW, entitled). Inspect timeline history before assuming near-term completion.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · HCD APR (½-mile radius)
Parcel & Assessor
- Lot size:
- 8,407 sq ft (0.19 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 5 RAINBOW LN
Zoning & Land Use
RS-7.5 — Single Fam Res (min 7,500 SF) (Mill Valley)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned RS-7.5 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned RS-7.5, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned RS-7.5, a single-family residential zone. The lot is 8,407 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
- Moderate 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: $1,904,000 – $2,576,000 · 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)
20 active or recent development projects (23 housing units across completed, permitted, and pipeline stages) and 153 total building permits recorded within ½ mile.
Developments Deserving Closer Investigation & Active Area Builders
- New home (Entitled)On this parcel
Active in "Entitled" for 3.2 yr (first record Sep 3, 2023) with no new permit activity recorded in 3.2 yr.
- MFR/Office Overlay (Entitled)0.35 mi NW
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 at 107 Montford Ave (Issued)0.35 mi S
Active in "Issued" for 3.9 yr (first record Dec 15, 2022) with no new permit activity recorded in 2.5 yr. High-impact scale (1 housing unit, $1,375,000 declared valuation across 1 permit).
- Accessory dwelling unit at 408 Laverne Ave (adu 408a) (Issued)0.4 mi SW
Active in "Issued" for 2.3 yr (first record Jul 12, 2024) with no new permit activity recorded in 14 mo. High-impact scale (1 housing unit, $2,700,000 declared valuation across 1 permit).
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 2023).