148 Morning Sun Ave
Mill Valley 94941 · Almonte · Unincorporated Marin · Coordinates: 37.88766, -122.52865
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 $2,072,000 ($1,823,000–$2,321,000).
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 5,009 sq ft lot. Local precedent is active with 3 ADU permits within ¼ mile over the last 36 months.
Source: Unincorporated Marin zoning · CA Gov. Code 66314 & 65852.21
- ✓ Documented permitted upgrades (+$22,572 contributory est.)
Public building records show issued construction/renovation work on this parcel (5 total permits, latest Dec 9, 2019).
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)
- ! 6 slow or stalled nearby projects within ½ mile
Closest lead: Accessory dwelling unit at 131 Yale Ave A (130 ft NW, 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 (~$24,278/yr at $2,072,000)
Sale triggers reassessment to 1.00% base + ~0.15% voter debt (~$2,023/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:
- 5,009 sq ft (0.11 ac)
- Assessor use:
- Single-Resid. - Improved
- Addresses on lot:
- 148 MORNING SUN 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 5,009 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: $1,823,000 – $2,321,000 · 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
- Accessory dwelling unit at 131 Yale Ave A (Issued)130 ft NW
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 home at 125 Morning Sun Ave (Issued)0.1 mi N
Active in "Issued" for 8.1 yr (first record Oct 15, 2018) with no new permit activity recorded in 7.8 yr. High-impact scale (1 housing unit, $900,000 declared valuation across 3 permits).
- New home at 217 Cleveland Ave (Issued)0.18 mi S
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).
- New commercial building at 100 Harvard Ave (Issued)0.24 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).
Entity-resolved builders & contractors in ½ mile: Greenstar Builders (2 on parcel, 2 in ½ mi · Remodel / interior alteration); Element Home Solutions (1 on parcel, 1 in ½ mi · HVAC / heat pump); Marin County Roofing (1 on parcel, 1 in ½ mi · Roof replacement); Gm Rigsby Electric (1 on parcel, 1 in ½ mi · Electrical / panel); Owner Builder (76 in ½ mi · Remodel / interior alteration).
Permit & Project History on This Parcel (5 permits, 0 grouped projects)
| Record # | Category | Status | Applied / Issued | Valuation | Description |
|---|---|---|---|---|---|
| 163482 | Remodel / interior alteration | Issued | Iss. Dec 9, 2019 | $20,000 | Struct Kitch Rmdl Rmove Struct Wall, Install Beam; Elec In Dining Room T.D. 11/5/19 |
| B19860 | Electrical / panel | Issued | Iss. Sep 14, 2019 | $3,000 | Upgrade electric meter panel — Service Upgrade |
| B19739 | HVAC / heat pump | Issued | Iss. Sep 4, 2019 | $19,980 | Replace AC, furnace, and duct — Replace Ductwork, Replace Mechanical Appliance |
| 162225 | Remodel / interior alteration | Issued | Iss. Aug 5, 2019 | $37,000 | Rmdl (2) Bthrms. |
| B12853 | Roof replacement | Issued | Iss. Jul 20, 2017 |