147 Harvard Ave
Mill Valley 94941 · Almonte · Unincorporated Marin · Coordinates: 37.88769, -122.53054
Executive Verdict · Public-Records Synthesis
Zoned R1-B1 in Unincorporated Marin with likely ADU & SB 9 infill eligibility and zero mapped flood, fire, or fault hazard overlaps; benchmark value $2,291,000 ($2,016,000–$2,566,000).
Upsides & Opportunities
- ✓ ADU & SB 9 infill pathways screen as likely eligible
Zoned R1-B1 supports ministerial ADU/JADU review plus SB 9 both two-unit development and ministerial urban lot split on a 8,407 sq ft lot. Local precedent is active with 4 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$154,800 contributory est.)
Public building records show issued construction/renovation work on this parcel (8 total permits, latest Aug 19, 2026).
Source: County of Marin Community Development Agency, Building Permits (unincorporated Marin) (parcel APN)
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 garage / accessory structure (175806): Issued after 22 mo (4.1× the 164d median) — slower than 90% of new garage / accessory structure permits in Unincorporated Marin (median 164d, 90th pct 485d, n=356).
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: Accessory dwelling unit at 131 Yale Ave A (450 ft E, 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)
- ! Year 1 Prop 13 tax reset (~$26,797/yr at $2,291,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,233/mo). Confirm exact Mello-Roos / CFD special assessments on the county tax bill.
Source: CA Const. Art. XIIIA (Prop 13) · County Tax Collector
Parcel & Assessor
- Lot size:
- 8,407 sq ft (0.19 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 147 HARVARD AVE
Zoning & Land Use
R1-B1 — Residential Single Family (Unincorporated Marin)
State Housing Pathways Screen (ADU & SB 9)
- ADU or junior ADULikely eligible
Zoned R1-B1 (single-family residential): state law allows ADUs where homes are allowed.
- SB 9: two homes on the lotLikely eligible
Zoned R1-B1, a single-family residential zone.
- SB 9: split into two lotsLikely eligible
Zoned R1-B1, 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
- 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 06041C0469F, 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: $2,016,000 – $2,566,000 · 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
Developments Deserving Closer Investigation & Active Area Builders
- New garage / accessory structure (175806) (Issued)On this parcel
Issued after 22 mo (4.1× the 164d median) — slower than 90% of new garage / accessory structure permits in Unincorporated Marin (median 164d, 90th pct 485d, n=356).
- Accessory dwelling unit at 131 Yale Ave A (Issued)450 ft E
Active in "Issued" for 4.8 yr (first record Jan 19, 2022) with no new permit activity recorded in 3.4 yr. High-impact scale (1 housing unit, $1,000,000 declared valuation across 1 permit).
- New commercial building at 100 Harvard Ave (Issued)0.14 mi W
Active in "Issued" for 23 mo (first record Dec 26, 2024) with no new permit activity recorded in 18 mo. High-impact scale ($6,500,000 declared valuation across 1 permit).
- New home at 217 Cleveland Ave (Issued)0.22 mi SE
Active in "Issued" for 9.7 yr (first record Feb 21, 2017) with no new permit activity recorded in 2.3 yr. High-impact scale (1 housing unit, $875,000 declared valuation across 1 permit).
Entity-resolved builders & contractors in ½ mile: Crescent Builders (1 on parcel, 2 in ½ mi · Addition (adds square footage)); East Peak Builders (1 on parcel, 2 in ½ mi · New garage / accessory structure); Aussie Roofing (2 on parcel, 2 in ½ mi · Roof replacement); Villa Family Construction (1 on parcel, 1 in ½ mi · Windows / doors / siding); Sun First (1 on parcel, 1 in ½ mi · Solar / battery storage).
Permit & Project History on This Parcel (8 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| B47971 | Other | Issued | Iss. Aug 19, 2026 | $39,650 | Replace Mechanical Appliance |
| B47775 | Windows / doors / siding | Issued | Iss. Aug 6, 2026 | $114,000 | Siding Replacement |
| B41328 | Solar / battery storage | Issued | Iss. Feb 19, 2025 | $100 | Remove & Replace Solar panels. |
| B41327 | Roof replacement | Issued | Iss. Feb 19, 2025 | $45,000 | Partial Re-Roof, Class 'A' FR Installation, w/Tapered ISO, Screw-fastened Densdeck. Modified Bitumen 2-ply roof system. … |
| 175806 | New garage / accessory structure | Issued | Iss. Jan 22, 2024 |