4 Tamalpais Ave
Belvedere 94920 · Belvedere · Coordinates: 37.87698, -122.47208
Executive Verdict · Public-Records Synthesis
Zoned R-15 in Belvedere with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $3,616,000 ($3,074,000–$4,158,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R-15 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 13,024 sq ft lot.
Source: Belvedere 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)
- ! Delayed or open permit activity on this parcel
New home: Active in "Issued" for 2.2 yr (first record Aug 15, 2024) with no new permit activity recorded in 2.2 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: 18 new homes (0.44 mi SE, issued). Inspect timeline history before assuming near-term completion.
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) · HCD APR (½-mile radius)
- ! Bulk building permits not published for Belvedere
Permit counts and nearby activity on this page may omit municipal counter records. Request a parcel permit report directly from the local building department.
Source: Source coverage registry (Belvedere)
Parcel & Assessor
- Lot size:
- 13,024 sq ft (0.30 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 4 TAMALPAIS AVE
Zoning & Land Use
R-15 (Belvedere)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R-15 (single-family residential): state law allows ADUs where homes are allowed. We read R-15 from the zoning code's name; we haven't checked it against Belvedere's code text.
- SB 9: two homes on the lotLikely eligible
Zoned R-15, a single-family residential zone. We read R-15 from the zoning code's name; we haven't checked it against Belvedere's code text.
- SB 9: split into two lotsLikely eligible
Zoned R-15, a single-family residential zone. We read R-15 from the zoning code's name; we haven't checked it against Belvedere's code text. The lot is 13,024 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
- 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 06041C0488E, 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: $3,074,000 – $4,158,000 · Status: Off market
HUD Small Area FMR (ZIP 94920) · FY 2026
Studio $2,820 · 1BR $3,380 · 2BR $4,100 · 3BR $5,230 · 4BR $5,420
Nearby Activity (½ mile radius, since —)
9 active or recent development projects (26 housing units across completed, permitted, and pipeline stages) and 0 total building permits recorded within ½ mile.
Developments Deserving Closer Investigation & Active Area Builders
- New home (Issued)On this parcel
Active in "Issued" for 2.2 yr (first record Aug 15, 2024) with no new permit activity recorded in 2.2 yr.
- 18 new homes (Issued)0.44 mi SE
Active in "Issued" for 2.6 yr (first record Apr 18, 2024) with no new permit activity recorded in 22 mo. High-impact scale (18 housing units, 4 deed-restricted affordable across 0 permits).
- New home (Issued)0.12 mi NW
Active in "Issued" for 2.7 yr (first record Mar 18, 2024) with no new permit activity recorded in 2.2 yr.
- New home (Entitled)0.13 mi N
Active in "Entitled" for 17 mo (first record Jun 19, 2025) with no new permit activity recorded in 17 mo.
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).